The 

Chemistry  and  Technology 
of  Printing  Inks 


BY 

NORMAN  UNDERWOOD 

CHIEF  OF  THE  INK-MAKING  DIVISION,    BUREAU  OF  ENGRAVING  AND 
PRINTING,    UNITED   STATES   TREASURY  DEPARTMENT 

AND 

THOMAS   V.  SULLIVAN 

ASSISTANT  CHIEF   OF  THE  INK-MAKING  DIVISION,   BUREAU  OF  ENGRAVING 
AND  PRINTING,   UNITED   STATES   TREASURY  DEPARTMENT 


Illustrated 


NEW  YORK 

D.  VAN  NOSTRAND    COMPANY 
25  PARK  PLACE 


COPYRIGHT,     IQIS,    BY 
D.    VAN    NOSTRAND    COMPANY 


PREFACE 

THE  authors  have  endeavored  in  the  preparation  of  this 
volume  to  prepare  a  concise  work  on  the  chemistry  and 
methods  of  manufacture  of  one  of  the  most  important 
materials  of  the  present  day. 

They  have  attempted  to  give  in  a  brief  and  practical 
but  yet  scientifically  correct  manner  the  many  facts  con- 
cerning the  raw  materials  and  finished  products  used  in 
this  industry  which  they  have  collected  during  a  number 
of  years  of  laboratory  work  and  manufacturing  experience. 

Obsolete  methods  and  materials  which  have  been  found 
to  have  no  value  in  the  art  on  account  of  modern  improve- 
ments or  excessive  cost  have  been  omitted. 

The  attempt  has  been  made  to  present  the  most  recent 
methods  of  manufacture  and  a  description  of  the  materials 
which  have  been  found  useful  in  the  art  in  a  clear  and  con- 
cise manner.  The  authors  have  spent  a  great  deal  of  time 
on  the  form  and  style  of  the  book  in  the  hope  that  it  may 
prove  valuable  and  serviceable  to  the  many  workers  in  this 
art. 

WASHINGTON,  D.  C.  N.  U. 

Sept.  i,  1914.  T.  V.  S. 


331006 


CONTENTS 

PAGE 

INTRODUCTION i 

PART  ONE 

TESTING  OF  MATERIALS 

LABORATORY  APPARATUS 15 

METHODS  OF  ANALYSIS 22 

PHYSICAL  TESTS  or  PIGMENTS 36 

PART  TWO 
MANUFACTURE  AND   PROPERTIES  OF    INK-MAKING  MATERIALS 

REDS 39 

BLUES 41 

YELLOWS 45 

GREENS 53 

ORANGES 55 

RUSSETS 60 

CITRINES 62 

BLACKS 63 

DlLUTENTS 74 

BASES 78 

ORGANIC  LAKES 84 

OILS 88 

TYPOGRAPHIC  VARNISHES 98 

REDUCERS 100 

DRIERS 102 

PART  THREE 
THE  MANUFACTURE  OF  PRINTING  INK 

GENERAL  CONSIDERATIONS 104 

EXPLANATION  OF  TERMS no 

PRINTING  INKS 112 

PLATE  INKS 112 

TYPOGRAPHIC  INKS 120 

DEFECTS  OF  INKS  AND  THEIR  REMEDIES 127 

INDEX 135 


INTRODUCTION 

THE  manufacture  of  printing  inks  today,  does  not, 
as  would  appear  at  first  glance,  consist  merely  in  the 
combining  together  of  pigments,  driers  and  vehicles  in 
certain  proportions. 

Besides  the  mere  combination  of  ingredients,  the  qual- 
ity, •  suitability  and  characteristics  of  these  materials 
must  be  considered  in  order  to  arrive  at  the  combina- 
tion that  will  be  both  chemically  and  physically  adapted 
to  give  the  best  results. 

In  order  to  determine  the  quality,  suitability  and  char- 
acter of  the  ingredients  that  go  into  printing  inks,  it  is 
necessary  to  have  some  knowledge  of  the  constitution 
and  methods  of  manufacture  of  these  materials,  and  to 
be  able  by  chemical  analysis  and  physical  tests  to  deter- 
mine whether  these  materials  have  been  properly  made 
and  whether  they  are  by  nature  fitted  for  the  work  they 
will  be  called  upon  to  do. 

If  the  characteristics  and  properties  of  all  the  raw 
materials  employed  in  the  printing-ink  industry  are  well 
understood  and  one  has  a  comprehensive  technical  knowl- 
edge of  the  results  to  be  obtained  by  the  use  of  a  cer- 
tain ink,  combinations  can  be  worked  out  that  will  give 
simple  formulas  and  ones  that  will  give  the  very  best 
working  inks  for  any  given  purpose,  with  the  added  ad- 
vantage that  they  will  be  easy  to  manipulate  to  meet 
any  unexpected  conditions  that  may  arise  in  printing. 


2  INTRODUCTION 

With  these  facts  in  mind,  we  have  divided  this  book 
into  three  parts:  namely,  methods  of  testing  raw  ma- 
terials; the  manufacture  and  properties  of  pigments  and 
varnishes;  and  the  manufacture  of  inks. 

We  have  not  devoted  any  space  to  the  chemical  analy- 
sis of  finished  inks  as  there  is  nothing  to  be  learned  by 
such  an  analysis,  except,  that  in  some  cases  it  may  give 
one  thoroughly  conversant  with  inks  some  slight  sugges- 
tion in  regard  to  the  duplication  of  an  ink.  A  general 
chemical  analysis  will  not,  however,  convey  any  idea  of  the 
essential  composition  of  the  ink.  It  will  show  the  percent- 
age of  oil  to  pigment,  whether  the  oil  is  linseed,  rosin,  or 
petroleum  oil,  and  in  a  general  way  what  the  pigment  is, 
but  it  shows  practically  nothing  concerning  the  physical 
condition  of  the  materials  before  manufacture  or  how  they 
were  combined;  and  unless  the  chemist  has  a  practical 
knowledge  of  ink  making,  it  does  not  show  even  this  much. 

For  example,  an  analysis  may  show  the  presence  of 
linseed  oil,  but  it  will  not  show  the  consistency  of  the  • 
oil  used  in  making  the  ink  nor  whether  two  or  three  dif- 
ferent consistencies  were  used.  Neither  will  it  show  if 
the  oil  was  combined  as  a  gum  varnish,  in  a  drier,  or 
whether  it  was  burnt  or  boiled.  It  will  not  show  whether 
the  drier  used  was  a  paste  drier,  a  japan  drier,  a  drier 
merely  added  dry  when  the  ink  was  made  or  incorporated 
into  the  oil  at  the  tune  of  burning  or  boiling,  or  whether 
it  was  introduced  in  the  form  of  a  metallic  soap.  It 
may  show  the  presence  of  a  mineral  oil,  but  it  will  not 
show  whether  the  oil  is  petrolatum,  paraffine  oil  or  kero- 
sene. If  aluminum  is  found,  it  will  not  show  whether 
it  was  added  as  a  base  to  the  ink,  or  whether  it  was  part 
of  a  lake  pigment  that  was  used. 


INTRODUCTION  3 

The  following  analyses  as  reported  by  'analysts  not 
familiar  with  the  manufacture  of  inks  together  with  their 
actual  composition  will  be  of  interest  in  this  regard. 

ANALYSIS  OF  AN  ENGRAVING  BLACK 

Oil  (partly  boiled  linseed) 30.31 

Carbon 38.90 

Silica  and  insoluble  silicates 9.50 

Calcium  Phosphate 9.04 

Calcium  Sulphate 2.82 

Calcium  Carbonate 1.83 

Oxide  Iron 26 

Berlin  Blue 7.34 

Items  marked  *  represent  62.35%  of  common  spent  bone  black. 

Now  this  ink  was  actually  composed  of  the  following 
materials : 

Bone  Black 37  % 

Vine  Black .16 

Prussian  Blue 7 

Paste  Drier 10 

Strong  Burnt  Plate  oil 4 

Medium  Burnt  Plate  oil 26 

In  this  ink  the  vine  black  and  strong  plate  oil  are  es- 
sential for  the  proper  color  and  working  properties,  yet 
their  presence  is  not  shown  by  the  analysis  and  could 
not  be  deduced  from  it. 

ANALYSIS  OF  A  BLACK  TYPOGRAPHICAL  INK 

Pigment 20     % 

Oil 80     " 

Oil 

Rosin  oil 60  " 

Rosin 22  « 

Linseed  Varnish 18  " 

Pigment 

Ash  and  oil  driers 2.5  " 

Prussian  Blue 3.9  " 

Carbon,  etc 93.6  " 


4  INTRODUCTION 

This  ink  actually  contained  only  about  4  per  cent  of 
linseed  oil,  the  basic  vehicle  being  a  varnish  made  from 
paraffine  oil  and  rosin,  the  rest  of  the  vehicle  consisting 
of  about  15  per  cent  second  run  rosin  oil  and  about  20 
per  cent  of  a  long  varnish  made  from  paraffine  oil,  asphal- 
tum,  wood  tar  and  kerosene  with  a  small  amount  of  japan 
drier.  An  ink  made  from  the  formula  as  shown  by  the 
analysis  would  not  make  an  ink  that  was  suitable  for  the 
purpose  this  ink  was  intended,  that  is  for  a  news  ink  run 
on  a  high-speed  web  press  on  news  paper. 

In  our  work  on  printing  inks  and  ink-making  materi- 
als, we  have  found  that  the  simpler  a  formula  is,  the  less 
trouble  one  will  have  with  the  ink,  and  in  the  event  of 
trouble,  it  will  be  easier  to  identify  the  cause  and  remedy 
the  defect.  There  has  always  been  a  tendency  in  the 
printing-ink  business,  as  conducted  in  a  practical  way, 
without  reference  to  the  technical  side  of  the  industry, 
to  have  formulas  for  inks,  particularly  those  for  special 
purposes,  as  complicated  as  possible.  This  is  due  mainly 
to  the  fact  that  these  inks  were  the  result  of  long  "rule 
of  thumb"  experiments,  in  which  the  different  materials 
were  added  until  the  combination  sought  for  was  ob- 
tained, and  partly  to  the  fact  that  every  ink  maker  and 
printer  has  a  number  of  trade  secrets  which  are  con- 
sidered to  be  of  great  value  in  making  inks  work  properly. 
The  value,  however,  of  these  secrets  is  in  most  cases 
doubtful. 

In  the  chapter  on  the  manufacture  of  printing  inks,  we 
have  not  given  any  working  formulas,  since  the  proper- 
ties of  materials  from  different  sources  are  quite  variable 
and  the  conditions  under  which  inks  are  used  are  liable 
to  be  very  different.  It  would  therefore  be  impossible 


INTRODUCTION  5 

to  give  exact  figures  that  would  be  of  any  service  and 
we  have  only  given  general  formulas  for  the  composition 
of  the  usual  classes  of  inks,  and  an  outline  of  the  de- 
fects liable  to  occur  and  the  remedies  that  we  have  found 
effective. 

The  information  in  this  book  represents  a  great  deal  of 
research,  both  in  the  laboratory,  and  in  the  works,  noth- 
ing being  taken  for  granted,  and  no  statement  is  made 
that  has  not  actually  been  proved  in  practice.  In  order 
to  avoid  useless  discussion  and  to  make  the  work  sim- 
pler, we  have  only  mentioned  those  things  which  we  have 
found  to  be  the  best  of  their  line.  There  are  a  great 
many  materials  and  methods  used  both  by  ink  manufac- 
turers and  printers,  to  accomplish  certain  things  which 
we  have  tried,  but  have  not  mentioned,  either,  because 
they  did  not  accomplish  the  result  claimed  for  them,  or 
because  we  found  something  else  would  do  so  better  or 
in  a  simpler  way. 

The  pigments  to  be  used  for  the  manufacture  of  print- 
ing inks  must  be  looked  at  from  a  different  standpoint 
and  judged  by  different  standards  than  those  to  be  used 
in  making  paints.  While  a  great  many  pigments  of  the 
same  chemical  composition  are  common  to  both  indus- 
tries, the  fact  that  one  of  them  under  certain  conditions 
is  acceptable  as  a  material  for  paint,  cannot  be  taken  as 
an  indication  that  it  will  be  equally  acceptable  when 
ground  into  a  printing  ink.  There  are  a  great  many  pig- 
ments, that,  while  they  are  available  for  use  as  paints, 
cannot  under  any  circumstances  be  used  for  ink  and  a 
number  of  very  satisfactory  ink-making  pigments  are  not, 
for  various  reasons,  adaptable  for  use  in  making  paints. 

The  chief  source  of  these  differences  can  be  easily  ex- 


6  INTRODUCTION 

plained  by  the  ultimate  use  of  the  two  products,  as  it 
can  readily  be  seen,  that  the  materials  which  are  used 
to  make  a  product  to  be  applied  with  a  brush,  in  a  thick 
layer,  and  whose  chief  function  is  covering,  can  differ 
widely  in  properties  from  those  that  are  to  be  used  in  a 
product  which  is  put  on  in  the  thinnest  possible  layer  and 
which  has  many  other  functions  to  perform  besides  that 
of  covering  surface. 

While  a  pigment  for  use  in  paint  must  be  judged,  to  a 
certain  extent,  by  its  color  strength,  its  body,  its  fineness 
of  grinding,  its  miscibility  with  other  pigments  and  the 
usual  vehicles,  its  durability  and  weathering  properties 
and  its  fastness  to  light,  a  pigment  for  use  in  printing 
ink  must  be  examined  into  for  all  of  these  properties  in 
the  minutest  way;  and  it  must  also  have  certain  other 
characteristics  not  necessary,  and  in  some  cases  not  de- 
sirable in  paint  pigments.  For  example,  there  are  pig- 
ments that,  when  mixed  with  a  large  quantity  of  oil  and 
thinned  with  turpentine,  work  well  under  a  brush  but 
show  shortness  and  lack  of  viscosity,  when  made  up  to 
the  consistency  of  ink,  and  which  will  not  distribute  at 
all  on  the  press.  Venetian  red,  an  admirable  paint  pig- 
ment, is,  on  account  of  its  hard,  gritty  nature,  of  prac- 
tically no  value  as  an  ink-making  pigment.  A  large 
number  of  aniline  lakes,  on  account  of  their  transparency 
and  lack  of  covering  power,  are  not  used  in  paints,  but 
for  this  very  reason  are  desirable  for  use  in  certain  kinds 
of  printing  inks. 

In  the  following  chapters  we  will  take  up  these  pig- 
ments and  discuss  them  only  from  the  standpoint  of  their 
availability  for  use  in  printing  inks,  making  no  mention 
of  those  pigments  not  suitable  for  this  work. 


INTRODUCTION  7 

Explanation  of  the  Terms  that  are  to  be  Used.  —  As 

many  of  the  technical  terms  used  to  describe  the  proper- 
ties of  pigments  and  inks  are  frequently  used  in  a  con- 
fusing and  indefinite  way,  the  following  explanation  of 
the  meaning  of  the  terms  hereafter  to  be  employed,  will 
help  to  eliminate  any  misunderstanding  in  their  use. 

Hue.  —  As  the  normal  spectrum  colors  merge  into  each 
other,  we  have  a  condition  where  one  color  has  a  slight 
mixture  of  the  other  in  it  and  this  slight  mixture  gives 
to  the  predominating  color  what  is  called  a  hue.  Thus 
if  we  have  red  slightly  tinged  with  violet,  this  is  called 
red  of  violet  hue.  On  the  other  hand  if  we  have  a  violet 
merging  into  red,  that  is,  if  a  slight  amount  of  red  tinges 
the  violet  the  result  is  a  violet  of  red  hue.  Green  in 
passing  into  blue  gives  us  first  a  green  of  blue  hue,  and 
then  a  blue  of  green  hue,  as  first  the  one,  and, then  the 
other  predominates. 

In  speaking  of  pigments  this  can  be  carried  further, 
to  mean  that,  when  two  pigments  are  mixed  to  produce 
a  new  color  and  the  color  of  one  pigment  predominates 
in  the  mixture,  the  resultant  color  will  have  the  hue  of 
the  predominating  pigment.  Thus  when  yellow  pre- 
dominates in  a  mixture  of  yellow  and  blue,  we  get  a  green 
of  yellow  hue  and  if  the  blue  predominates,  we  get  a 
green  of  blue  hue. 

Tint.  —  When  a  normal  spectrum  color  or  hue  of  that 
color  is  mixed  with  white,  we  get  a  gradation  of  that 
color  lighter  in  appearance  and  this  is  called  a  tint  of 
the  original  color.  In  speaking  of  pigments  a  tint  means 
a  pigment  lightened  by  the  admixture  of  white. 

Shade.  —  When  a  normal  spectrum  color,  or  one  of 
its  hues,  is  mixed  with  a  small  amount  of  black  or  its 


8  INTRODUCTION 

complementary  color,  we  get  a  gradation  of  that  color 
darker  in  appearance  than  the  original  and  this  is  called 
a  shade  of  the  color. 

The  term  shade  is  frequently  misused  to  convey  the 
idea  of  hue.  In  the  following  pages  the  word  shade  will 
be  used  to  convey  the  idea  of  a  pigment  darkened  by 
the  addition  of  black  or  another  pigment  complemen- 
tary to  it. 

Top  Hue  and  Under  Hue.  —  When  different  thicknesses 
of  a  medium  are  used,  there  is  in  some  cases  a  different 
amount  of  color  absorption  for  the  varying  thicknesses 
of  the  medium  and  this  causes  a  variation  in  the  color 
or  the  hue  of  the  medium.  Thus  a  dilute  or  thin  solu- 
tion of  magenta  shows  a  pink  of  blue  hue,  while  a  so- 
lution of  very  great  depth  or  strength  is  a  deep  red. 
Cobalt  glass  when  very  thin,  shows  a  blue  color,  while  as 
the  thickness  increases,  it  becomes  purple  and  finally  if 
a  sufficiently  great  thickness  be  employed  the  color  is  a 
deep  red. 

The  cause  of  this  action  is  that  there  is  an  unequal  co- 
efficient of  absorption  between  the  different  densities.  At 
varying  densities  the  absorption  curve  takes  in  or  ex- 
cludes different  parts  of  the  spectrum  and  the  result  is 
that  the  apparent  color  is  of  different  hues,  depending  on 
the  proportionate  increase  or  decrease  of  the  absorption. 

When  the  medium  is  an  opaque  pigment  and  is  spread 
on  paper  in  a  solid  band  so  as  to  completely  shut  out 
the  white  of  the  paper  or  if  the  pigment  is  viewed  in  a 
mass,  it  shows  the  absorption  that  a  dense  solution  would 
show;  but  when  diluted  with  a  white  pigment  or  printed 
thinly  on  paper  we  get  the  same  condition  of  unequal 
absorption  as  occurs  in  dilute  or  thin  solutions,  and  a 


INTRODUCTION  9 

hue  of  the  original  color  is  the  result,  the  white  pigment 
or  the  white  light  of  the  paper  acting  as  a  dilutent.  On 
account  of  this  we  often  get  a  red  of  yellow  hue  in  the 
mass  while  on  rubbing  or  printing  it  out  thinly  or  dilut- 
ing with  white  we  get  a  red  of  blue  hue.  From  this 
explanation  it  can  be  readily  seen  that  we  can  have  a 
number  of  these  variations  between  the  material  in  mass 
and  the  same  material  diluted,  or  printed  out  thinly. 
The  hue  of  the  color  when  taken  in  the  mass  or  undi- 
luted we  will  call  the  top  hue  while  the  diluted  or  thinly 
spread  out  hue  we  will  call  the  under  hue  of  a  color. 

Color  Strength.  —  By  the  term  color  strength  of  a  pig- 
ment is  meant  the  actual  amount  of  color  it  contains  and 
is  measured  by  its  tinting  power  when  mixed  with  white. 
This  of  course  is  a  measure  of  the  relative  power  a  pig- 
ment has  to  impart  its  hue  or  color  to  another  pigment. 
The  color  strength  of  a  pigment  varies  inversely  with  its 
crystalline  character,  the  more  amorphous  a  pigment  is 
the  greater  will  be  its  color  strength. 

Abrasive  Quality.  —  If  a  pigment  contains  any  hard 
material  it  is  apt  to  exert  an  abrasive  action  on  plates, 
forms  and  cuts  and  to  wear  down  the  fine  lines  so  that 
sharpness  and  definition  will  be  lacking.  This  not  only 
destroys  the  effectiveness  of  the  work  but  also  shortens 
the  life  of  the  plate  or  cut. 

Fineness.  —  This  word  is  used  in  its  ordinarily  accepted 
meaning.  In  this  connection  it  is  well  to  note  that  tak- 
ing the  term  abrasive  quality  in  the  sense  shown  above, 
a  material  can  be  quite  fine  and  at  the  same  time  can  be 
abrasive.  A  great  degree  of  fineness  is  necessary  in  all 
pigments  to  be  used  in  ink  making  not  only  on  account 
of  the  fine  lines  and  delicate  tone  effects  which  would 


io  INTRODUCTION 

not  be  brought  out  unless  the  pigment  was  ground  very 
finely  but  also  because  a  coarse  pigment  has  a  tendency 
to  collect  into  balls  and  to  give  a  granular  effect  to  the 
ink.  Precipitated  colors  frequently  appear  coarse  but 
when  rubbed  under  the  finger  this  apparent  coarseness 
disappears. 

Oil  Absorption.  —  On  account  of  differences  in  the  phys- 
ical structure  of  pigments  the  amount  of  oil  necessary 
to  make  a  thin  paste  varies,  some  pigments  taking  more 
than  others;  the  measure  of  this  quality  is  called  the  oil 
absorption  of  a  pigment. 

Livering.  —  When  an  ink,  on  standing,  thickens  to  a 
spongy,  rubber-like  mass  it  is  said  to  liver.  This  is  due 
to  a  chemical  action  between  the  pigment  and  the  vehi- 
cle, such  as  the  rapid  oxidation  of  the  oil,  or  the  forma- 
tion of  a  soap.  When  a  pigment  shows  a  tendency  to 
liver  it  cannot  be  regarded  as  a  good  ink-making  pigment. 
*  Shortness.  —  If  a  pigment  when  mixed  with  a  large 
quantity  of  oil  still  remains  stiff  or  cannot  be  drawn  out 
into  a  string  between  the  fingers  but  breaks,  it  is  said  to 
be  short.  While  there  are  some  classes  of  work  that  re- 
quire an  ink  of  a  certain  degree  of  shortness,  as  a  general 
rule,  pigments  that  show  this  property  are  not  suited  for 
making  inks. 

Flow  and  Length.  —  Flow  is  the  property  of  a  pigment 
to  combine  with  a  good  body  the  abilty  to  run  and  feed 
well  on  the  press.  An  ink  that  flows  well  must  also  have 
the  property  of  being  drawn  out  into  a  string  between 
the  fingers  and  this  is  called  length.  Thus  each  of  these 
terms  suggests  or  includes  the  other;  they  are  both  some- 
times spoken  of  under  the  name  of  viscosity.  For  all 
classes  of  work  these  properties  are  very  essential  and  a 


INTRODUCTION  II 

pigment  that  does  not  show  them  to  some  extent  should 
be  avoided. 

Tack  and  Softness.  —  Tack  is  that  property  of  cohesion 
between  particles  of  ink  that  can  best  be  described  as 
the  pulling  power  of  the  ink  against  another  surface. 
When  there  is  very  little  cohesion  and  the  property  of 
tack  is  almost  absent  we  have  what  we  shall  designate 
as  softness. 

Body  Color.  —  Body  color  is  the  color  of  the  dry  pig- 
ment before  it  is  mixed  with  a  vehicle.  The  addition  of 
a  vehicle  frequently  makes  a  decided  difference  in  the 
color  of  a  pigment. 

Transparency.  —  Transparency  will  be  used  in  the 
general  sense  of  the  word,  namely  a  pigment  or  ink  that 
allows  color  or  light  from  another  source  to  pass  through 
it. 

Opacity.  —  Opacity  is  the  property  of  absolutely  stop- 
ping the  transmission  of  light  or  color  from  another 
source.  A  transparent  color  can  be  rendered  more  or 
less  opaque  by  the  addition  of  a  base,  while  many 
opaque  pigments  can  be  made  to  some  extent  transparent 
if  they  are  laid  on  or  printed  in  a  thin  film  and  some 
few  can  be  made  to  appear  transparent  to  a  slight  degree 
by  the  addition  of  other  materials.  The  opacity  or 
covering  power  varies  as  does  the  color  strength  with 
the  crystalline  character  of  the  pigment. 

Body.  —  The  body  of  a  pigment  is  the  measure  of  its 
density.  This  term  is  variously  used,  generally  to  con- 
vey the  idea  of  a  property  not  readily  explainable.  Thus 
it  is  sometimes  spoken  of  to  convey  the  idea  of  covering 
power,  and  this  is  due  to  the  fact  that  the  denser  an  ink 
is  the  more  covering  power  it  will  have.  As  regards  its 


12  INTRODUCTION 

use  in  this  volume  it  is  the  measure  of  the  consistency 
and  density  of  the  ink.  Thus  a  stiff  ink  that  stands  is 
said  to  have  a  good  body  while  an  ink  that  is  soft  and 
runny  is  said  to  lack  body. 

Incompatibility.  —  Incompatibility  means  that  for  some 
reason,  physical  or  chemical,  a  pigment  cannot  be  used 
with  another  pigment  or  with  certain  vehicles  or  under 
certain  circumstances.  The  fact  that  we  cannot  use 
lead  colors  with  those  containing  sulphur  is  a  well- 
known  example  of  this.  Another  illustration  is  the  fact 
that  colors  affected  by  alkalies  should  not  be  used  to 
print  labels  for  soap  or  lye  cans. 

Bleeding.  —  Certain  pigments  when  mixed  with  water 
or  oil  or  any  of  the  various  printing-ink  vehicles  are 
partially  soluble  and  this  solubility  is  called  bleeding. 
Pigments  that  bleed  are  not  of  much  value  for  making 
printing  inks  as  they  are  apt  to  strike  through  the  paper 
or  color  the  edge  of  the  work.  A  pigment  that  is  to  be 
used  in  dry  work  need  not  be  entirely  insoluble  in  water 
but  as  a  general  rule  a  pigment  that  bleeds  has  not  been 
properly  made. 

Fastness  to  Light.  —  This  is  used  in  the  ordinary  sense 
of  the  word,  that  is,  to  mean  the  degree  of  resistance  the 
color  has  to  the  changing  action  of  ordinary  light. 

Atmospheric  Influences.  —  Closely  allied  to  fading  and 
sometimes  attributed  to  it,  are  other  changes  both  phys- 
ical and  chemical  caused  by  the  influence  of  the  atmos- 
phere. 

These  may  be  produced  in  various  ways,  by  oxidation, 
reduction,  the  solvent  action  of  gases  and  by  chemical 
combinations  between  the  pigment  and  acid  radicals 
present  in  the  air  or  on  account  of  changes  in  the  phys- 


INTRODUCTION  13 

ical  form  of  the  color,  due  to  dryness,  moisture  or  ex- 
tremes of  temperature.  The  action  of  sulphur  gases  on 
lead  pigments  and  the  greenish  hue  that  prussian  blue 
assumes  from  exposure  to  oxidizing  influences  are  com- 
mon examples. 


PART   ONE 

TESTING  OF   MATERIALS 

GENERAL    LABORATORY  APPARATUS,    CHEMICAL   AND 
PHYSICAL  TESTS 

SECTION    ONE.     LABORATORY   APPARATUS 

THE  following  methods  of  analysis  and  tests  of  ink- 
making  materials  have  been  compiled  from  various  sources 
too  numerous  and  varied  for  us  to  attempt  to  give  any 
credit.  All  of  them  have  been  practically  tried  by  the 
authors  and  found  to  be  satisfactory. 

As  the  results  obtained  in  testing  depend  entirely  on 
the  accuracy  and  uniformity  with  which  the  work  is  done 
and  as  this  accuracy  and  uniformity  depend  in  a  great 
measure  on  the  apparatus  employed,  a  brief  description 
of  the  standard  apparatus  employed  by  the  authors  in 
testing  inks  and  ink-making  materials  will  be  given. 
Some  of  this  apparatus  is  in  general  use  for  testing  pig- 
ments, inks  and  paints,  some  has  been  adapted  from  other 
sources  and  some  is  original  with  us. 

Muller  and  Slab.  -  -  The  slab  used  for  rubbing  colors 
should  be  of  smooth  polished  marble,  perfectly  level,  set 
in  a  heavy  framed  table  that  must  be  perfectly  rigid. 
The  muller  should  be  made  of  some  close-grained,  hard 
material  such  as  lithographic  stone  or  a  smooth,  fine- 
grained marble.  It  should  be  conical  in  shape  to  give 


16  CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

a  good  purchase  to  the  hands  and  to  allow  of  its  being 
shoved  with  the  maximum  of  downward  pressure.  The 
one  in  use  in  our  laboratory  is  8  inches  high,  3  inches 
in  diameter  at  the  bottom  and  weighs  about  4  pounds. 
The  place  gripped  by  the  hands  is  slightly  roughened  to 
give  a  good  purchase  and  the  bottom  is  highly  polished. 
The  surface  of  the  slab  must  be  absolutely  true  and 
smooth  so  that  the  pressure  will  be  uniform  and  to  avoid 
having  the  particles  of  color  gather  where  they  will  not 
get  sufficient  rubbing.  A  cut  of  the  slab  and  muller, 
showing  the  color  rubbed  out,  is  shown  in  Figure  i. 


FIGURE  i.  —  MULLER  AND  SLAB,  SHOWING  METHOD 
OF  RUBBING  OUT  COLORS. 

Electric  Muffle  Furnace.  —  An  electric  muffle  furnace 
will  be  found  invaluable,  as  with  it  almost  any  range  of 
temperature  can  be  obtained  and  it  is  far  superior  to  the 
bunsen  burner  for  ashing  materials  and  burning  precipi- 
tates. It  is  easily  regulated  and  will  reproduce  at  any 


TESTING  OF  MATERIALS 


time  a  definite  condition  of  temperature  used  previously, 
so  that  work  can  be  duplicated  at  different  times  under 
exactly  similar  conditions. 

Electric  Combustion  Furnace.  —  An  electric  combus- 
tion furnace  will  also  be  found  to  be  far  more  satisfactory 
than  the  ordinary  gas  combustion  furnace. 

Constant  Temperature  Oven.  -  -  The  most  satisfactory 
constant  temperature 
oven  is  an  electric  one. 
The  one  we  use  has  an 
easily  controlled  range 
from  75°  to  150°  C. 

There  are  also  electri- 
cal hot  plates  and  heat- 
ing apparatus  of  almost 
every  description  which 
are  more  satisfactory 
than  the  gas  burning 
ones,  and  by  the  use  of 
these  electrical  devicea 
in  a  laboratory  the 
danger  of  fire  is  almost 
entirely  eliminated. 

Mixing  Machine.  - 
For  mixing  small  ex- 
perimental batches  of 
ink  we  use  an  electrically  driven  mixer,  the  picture  of 
which  is  shown  in  Figure  2.  This  mixer  takes  an  iron 
mixing  pan  Q|  inches  in  diameter  and  4  inches  deep, 
which  will  hold  about  2  pounds  of  material.  The  dry 
color  and  oil  are  weighed  directly  into  the  tared  pan  and 
it  is  then  set  on  the  mixer. 


FIGURE  2. — LABORATORY  MIXER. 


i8 


CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 


FIGURE  3.  —  ULTRA-VIOLET  LIGHT  AND  CASE  FOR 
TESTING  THE  EFFECT  OF  LIGHT  ON  COLORS. 


Grinding  Mill. 
-  For  grinding 
experimental 
batches  of  ink 
under  the  same 
conditions  as  will 
occur  in  ordinary 
work  (and  this 
is  an  important 
factor,  as  all  lab- 
oratory work  of 
this  sort  should 
be  done  as  closely 
as  possible  under 
conditions  that 
can  be  dupli- 
cated on  a  prac- 
tical scale),  we 
have  a  small  mill 
made  by  the  Kent 
Machine  Works 
which  is  in  every 
way  a  duplicate 
of  their  large 
three-roll  ink  mill. 
Ultra-Violet 
Light— For  test- 
ing the  fastness 
to  light  of  various 
pigments  and 
dyes  we  use  an 
ultra-violet  light. 
This  light  is 


TESTING  OF  MATERIALS  19 

mounted  in  a  sheet-iron  hood  3  feet  by  3  feet  at  the 
base,  sloping  up  in  the  form  of  a  pyramid  enclosing  the 
lamp  as  shown  in  Figure  3.  The  bottom  of  the  light 
is  set  21  inches  above  the  bottom  of  the  hood,  which  is 
fitted  with  a  hinged  door  and  drawer  for  convenience 
in  placing  the  samples.  As  the  rays  given  off  by  this 
light  are  very  injurious  to  the  eyes,  a  look-in-hole  is 
provided,  high  enough  up  so  that  the  light  itself 
can  be  seen,  and  is  covered  with  a  Hallauer  No.  64  glass 
for  cutting  off  the  ultra-violet  rays.  This  light  develops 
about  the  same  intensity  as  strong  sunlight  but  has  the 
advantage  of  being  always  uniform  and  can  be  used  in 
any  sort  of  weather. 

Balances.  —  An  accurate  analytical  balance  is,  of  course 
a  necessity.  For  rougher  yet  somewhat  accurate  work 
where  small  amounts  are  to  be  weighed  a  small  "prescrip- 
tion" balance  will  be  found  useful  as  will  also  a  balance 
of  the  "Robervahl"  type  with  a  capacity  of  from  5  to  10 
pounds.  For  ordinary  heavy  work  a  small  platform  scale 
that  will  weigh  down  to  ounces  and  up  to  100  pounds  is 
necessary. 

Microscope.  —  A  good  microscope  with  a  photographic 
attachment  is  also  a  great  adjunct  in  work  on  pigments, 
especially  in  determining  their  physical  characteristics 
and  the  bases  on  which  aniline  lakes  are  precipitated. 
This  branch  of  work  is  only  beginning  to  be  recognized 
and  given  its  proper  place  in  the  color  testing  laboratory. 

Filtering  Apparatus.  —  For  filtering  large  experimental 
batches  of  color  a  small  filter  press  may  be  used  but  this 
will  not  be  found  any  more  satisfactory  than  the  more 
simple  rectangular  frame  with  pins  from  which  a  filter 
cloth  is  suspended. 


20          CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Oil  Tanks  and  Cups.  —  Several  small  copper  tanks 
with  covers  and  wide  opening  spigots  should  be  used  to 
hold  oils  and  varnishes  for  use  in  the  laboratory  and  we 
have  found  a  few  cups  with  tops  that  lift  back  and  a  lip 
fashioned  after  the  ordinary  molasses  pitcher  are  very  use- 
ful when  weighing  out  oils,  varnishes  and  other  liquids. 

Glass  Plates.  —  For  testing  and  comparing  color 
strength  and  top  hue  a  thin  colorless  glass  plate  similar 
to  those  used  to  make  photographic  slides  should  be 
provided. 

Thermometers.  —  The  laboratory  should  be  provided 
with  sufficient  thermometers  of  various  ranges  and  an 
accurate  pyrometer  will  be  found  of  great  use  in  deter- 
mining high  temperatures. 

Hydrometers.  —  A  set  of  6  hydrometers  divided  as 
follows  will  be  found  to  give  a  very  useful  range;  Specific 
Gravity,  .700  to  .800,  .800  to  .900,  .900  to  i.ooo,  i.ooo 
to  1.200,  1.200  to  1.400  and  1.400  to  1.600.  These  in- 
struments should  be  graduated  to  read  .5  of  a  degree  in 
the  fourth  place.  A  set  giving  Beaume  readings  for 
getting  correct  strength  solutions  for  precipitations  and 
the  like  is  also  necessary. 

Viscosimeters.  —  The  viscosimeter  employed  by  us  for 
the  determination  of  viscosity  in  raw  oils  is  the  regular 
type  of  Engler  viscosimeter,  standardized  against  water. 
Figure  4  shows  the  one  used  for  testing  boiled  or  burnt 
oils  and  varnishes.  It  is  a  copper  cylinder  with  a  steam 
jacket  so  that  the  oil  and  jacket  can  be  kept  at  a  constant 
temperature  of  100°  C.  Its  inside  dimensions  are  12 
inches  by  4^  inches,  and  it  has  marks  so  that  the  same 
amount  of  oil  or  varnish  can  be  used  each  time.  The 
amount  of  oil  used  in  the  one  in  use  in  our  laboratory  is 


TESTING  OF  MATERIALS 


21 


1200  c.c.,  and  of  this 
amount  1000  c.c.  are  run 
out  in  the  test.  The  bottom 
of  the  cylinder  is  pitched 
slightly  to  make  the  flow 
even  and  the  orifice  out 
of  which  the  oil  flows  is  a 
stop  cock  with  a  J  inch 
opening  fitted  with  a  long 
handle  so  that  it  operates 
easily  and  quickly.  The 
jacket  is  fitted  with  a  ther- 
mometer as  is  also  the  top 
of  the  cylinder.  The  ther- 
mometer in  the  top  ex- 
tends well  into  the  oil  about 
in  the  center  of  the  viscosi- 
meter;  the  one  in  the 
jacket  shows  the  temper- 
ature of  the  jacket.  The 
apparatus  should  be  leveled 
when  set  and  should  be 
fastened  securely. 

We  find  this  piece  of 
apparatus  invaluable  in  de- 
termining the  consistency 
of  oils  and  varnishes  of 
heavy  viscosity.  The  re- 
sults are  only  relative, 
however,  as  the  instrument 
is  standardized  against  oils 

and    varnishes    known    to  FIGURE  4.  —  VISCOSIMETER  FOR  TESTING 
,  .  f  HEAVY  BODIED  OILS  AND  VARNISHES. 

be  satisfactory. 


22  CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Steam  Jacketed  Kettle.  —  A  steam  jacketed  kettle  cf 
the  regular  type  holding  about  five  or  ten  gallons  will 
be  found  indispensable. 

Crocks  and  Miscellaneous.  —  Several  stoneware  crocks 
from  five  to  twenty  gallons  capacity  should  be  provided 
for  precipitating  colors. 

A  motor-driven  stirring  machine,  a  number  of  heavy 
glass  rods,  smooth  metal  bars  and  wooden  paddles,  and 
several  low  wooden  trestles  should  also  find  a  place  in 
the  laboratory  equipment. 

SECTION   TWO.     METHODS   OF  ANALYSIS 

LINSEED  OIL 

Specific  Gravity.  —  Specific  gravity  may  be  determined 
with  a  pyknometer  or  hydrometer  at  15.5°  C.  For  most 
control  work  an  accurate  hydrometer,  reading  to  one-half 
a  degree  in  the  fourth  place  will  be  found  as  satisfactory 
as  a  pyknometer,  providing  the  oil  is  uniformly  cooled, 
the  hydrometer  immersed  without  touching  the  sides  of 
the  jar  and  the  reading  carefully  taken.  There  should 
be  no  air  bubbles  in  the  liquid  at  the  time  of  reading. 

The  specific  gravity  of  a  raw  oil  should  be  above  .931, 
but,  inasmuch  as  ageing,  blowing  and  other  permissible 
treatments  that  do  not  bring  the  oil  into  the  class  of  a 
boiled  oil,  increase  the  gravity,  it  is  useless  to  give  a  high 
limit  for  specific  gravity.  Boiled  or  burnt  oils,  or  oils 
that  have  had  driers  added  to  them  show  a  still  higher 
gravity. 

Viscosity.  —  The  viscosity  should  be  taken  on  an 
Engler  viscosimeter  at  20°  C.,  water  being  taken  as  the 
standard.  It  is  essential  in  order  to  get  concordant 


TESTING  OF  MATERIALS  23 

results  that  both  the  water  in  the  jacket  and  the  oil 
remain  at  the  proper  temperature  throughout  the  whole 
operation. 

Flash.  —  The  flash  should  be  taken  in  a  Cleveland 
open  fire  tester  or  some  similar  instrument  in  the  follow- 
ing manner:  The  cup  is  put  in  the  center  of  a  ring  of 
asbestos,  extending  all  around  it  about  2  inches,  and  set 
on  a  tripod  over  a  bunsen  burner  with  the  flame  so 
regulated  that  the  temperature  of  the  oil  will  rise  about 
9°  C.  per  minute.  As  a  test  flame,  use  an  ordinary  blow 
pipe  attached  to  a  rubber  tube.  Begin  testing  when  the 
temperature  of  the  oil  reaches  250°  C.  and  test  for  every 
rise  of  three  degrees.  When  applying  the  test  flame  move 
it  slowly  across  the  oil  in  front  of  the  thermometer  a 
little  above  the  surface  of  the  oil.  The  flash  is  the  low- 
est temperature  at  which  the  vapors  above  the  oil 
flash  and  go  out.  Care  should  be  taken  that  the  oil  is 
not  foaming  when  the  flame  is  applied,  as  the  bubbles 
will  burst  and  give  an  incipient  flash  which  will,  of  course, 
be  low. 

Fire  Point.  —  After  determining  the  flash  point,  con- 
tinue heating  the  oil  until  the  vapors  when  ignited  con- 
tinue to  burn.  The  temperature  at  which  this  occurs  is 
called  the  fire  point. 

Drying  on  Lead  Monoxide.  —  This  test  is  similar  to 
Livache's  drying  test,  only  litharge  is  used  instead  of 
precipitated  lead.  Weigh  out  about  5  grams  of  lith- 
arge into  a  tared  watch  glass,  spreading  the  litharge  on 
the  bottom  of  the  glass;  distribute  as  evenly  as  pos- 
sible over  the  litharge  from  .2  to  .5  grams  of  oil.  Take 
the  exact  weight  of  the  oil  and  the  exact  weight  of  the 
watch  glass,  oil,  and  litharge,  expose  to  the  air  and 


24         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

light  for  from  76  to  96  hours,  weigh  again  and  the  gain 
is  calculated  in  percentage  from  the  original  weight  of 
the  oil  used.  A  chemically  pure  litharge  must  be  used 
in  this  determination  to  get  uniform  results. 

Acid  Value.  —  Ten  grams  of  oil  are  weighed  into  a 
200  c.c.  Erlenmeyer  flask  and  50  c.c.  of  neutral  alcohol 
added,  heat  on  a  steam  bath  for  one-half  hour,  cool  and 
titrate  with  one-tenth  normal  sodium  hydrate,  using 
phenolphthalein  as  an  indicator;  calculate  the  acid 
value  as  milligrams  of  potassium  hydrate  per  gram  of 
oil.  The  acid  value  varies  as  does  the  gravity  with  age 
and  blowing  or  treatment  but  should  be  less  than  8. 

Saponification.  —  Weigh  2  to  3  grams  of  oil  into  a 
200  c.c.  Erlenmeyer  flask:  add  30  c.c.  one-half  normal 
alcoholic  potash,  connect  with  a  reflux  condenser,  heat 
on  a  steam  bath  for  i  hour;  titrate  with  one-half  normal 
sulphuric  acid  using  phenolphthalein  as  an  indicator. 
Always  run  two  blanks  with  the  alcoholic  potash.  From 
the  difference  between  the  cubic  centimeters  of  acid 
required  by  the  blanks  and  the  sample  calculate  the 
saponification  number  in  terms  of  milligrams  of  potas- 
sium hydrate  to  one  gram  of  oil.  The  saponification 
number  of  linseed  oil  should  be  about  190. 

Unsaponifiable  Matter.  —  Saponify  5  grams  of  oil  with 
about  200  c.c.  one-half  normal  alcoholic  potash  for  an 
hour  on  a  steam  bath,  using  a  reflux  condenser  and  evap- 
orate the  alcohol;  take  up  in  water  and  transfer  to  a 
separatory  funnel,  cool,  shake  out  with  two  portions  of 
50  c.c.  each  of  petroleum  ether;  wash  the  petroleum 
ether  twice  with  water,  evaporate  the  petroleum  ether 
and  weigh  the  unsaponifiable  matter,  which  in  raw  lin- 
seed oil  should  not  be  over  1.5  per  cent. 


TESTING  OF  MATERIALS  25 

Iodine  Number.  —  Weigh  out  from  .2  to  .25  gram  of  oil, 
transfer  to  a  350  c.c.  bottle  with  a  well  ground  glass 
stopper:  dissolve  the  oil  in  10  c.c.  of  chloroform  and 
add  30  c.c.  of  Hanus  solution:  let  it  stand  with  occa- 
sional shaking  for  one  hour:  add  20  c.c.  of  a  10  per  cent 
solution  of  potassium  iodide  and  150  c.c.  of  water  and 
titrate  with  standard  sodium  thiosulphate,  using  starch 
as  an  indicator.  Blanks  must  be  run  each  time  and  from 
the  difference  between  the  amounts  of  sodium  thiosul- 
phate required  by  the  blank  and  the  sample  calculate 
the  iodine  number  (centigrams  of  iodine  absorbed  by 
one  gram  of  oil). 

The  Hanus  solution  is  made  by  dissolving  13.2  grams 
of  iodine  in  1000  c.c.  of  glacial  acetic  acid  and  adding 
3  c.c.  of  bromine. 

Foots  and  Turbidity.  —  Let  one  liter  of  oil  stand  in 
a  clear  glass  bottle  for  eight  days  and  note  the  amount 
of  sediment  formed.  In  very  cold  weather  the  oil  will 
sometimes  show  a  turbidity  due  to  the  freezing  out  of 
fats  of  very  high  melting  point.  It  is  therefore  well  in 
cold  weather  to  heat  a  portion  of  the  oil  to  about  100°  C. 
and  allow  it  to  cool.  If  the  turbidity  does  not  return 
the  oil  should  not  be  reported  as  turbid. 

Ash.  —  Burn  about  20  grams  in  a  porcelain  dish  and 
weigh  the  ash.  A  pure  raw  linseed  oil  should  contain 
only  a  trace  of  ash.  In  a  boiled  oil  the  ash  will 
show  the  metallic  driers.  Make  a  qualitative  test  for 
these. 

Break.  —  Heat  50  c.c.  of  oil  in  a  small  beaker  up  to 
300°  C.  rapidly.  If  a  jelly-like  mass  separates  out, 
the  oil  has  broken.  This  determination  is  influenced  by 
the  rate  of  heating  to  such  an  extent  that  it  is  difficult, 


26         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

unless  the  heating  is  done  very  rapidly,  to  get  the  same 
oil  to  act  twice  in  the  same  way. 

Drying  with  Manganese  Borate.  —  One  gram  of  oil 
and  .2  gram  of  manganese  borate  are  spread  on  a  glass 
plate  very  thin  and  the  time  of  drying  noted. 

Rosin.  —  (Liebermann-Storch  Test.)  To  20  grams  of 
oil,  add  50  c.c.  of  alcohol,  heat  on  the  steam  bath  for 
about  fifteen  minutes,  cool,  decant  the  alcohol,  evaporate 
to  dryness,  add  5  c.c.  of  acetic  anhydride,  warm,  cool 
and  add  a  drop  of  sulphuric  acid,  1.53  specific  gravity. 
Rosin  or  rosin  oil  will  give  a  fugitive  violet  color.  The 
conclusiveness  of  this  test  is  open  to  doubt. 

DETERMINATION  OF  CALCIUM  CARBONATE  IN 
PARIS  WHITE 

Weigh  .5  gram  of  the  sample  into  an  Erlenmeyer  flask, 
add  60  c.c.  of  fifth  normal  hydrochloric  acid,  close  the 
flask  with  a  reflux  condenser  about  2  feet  long.  Boil 
until  steam  comes  from  the  tube;  remove  the  flask  and 
wash  the  tube  into  it,  add  a  few  drops  of  phenolphthalein 
and  run  in  one-fifth  normal  «alkali  until  the  color  just  turns 
red.  Calculate  the  calcium  carbonate  from  the  number 
of  c.c.  of  alkali  required.  Lime  may  also  be  determined 
gravimetrically  by  precipitation  in  the  following  manner: 
.5  gram  of  the  sample  is  dissolved  in  hydrochloric  acid, 
the  insoluble  matter  is  filtered  off,  the  filtrate  is  made 
alkaline  with  ammonia  in  slight  excess  and  boiled.  If 
iron  and  aluminum  precipitate,  the  solution  is  filtered 
and  washed  with  hot  water,  the  filtrate  to  which  more 
ammonia  has  been  added  is  then  boiled  and  a  boiling 
solution  of  ammonium  oxalate  is  added  and  the  solution 
allowed  to  boil  for  about  fifteen  minutes,  allowed  to 


TESTING  OF  MATERIALS  27 

stand  until  settled  and  filtered;  wash  with  hot  water; 
burn  off  filter  paper,  blast  for  fifteen  minutes  and  weigh 
as  calcium  oxide.  By  burning  and  weighing  the  insol- 
uble residue  the  amount  can  be  determined  as  can  also 
the  iron  and  aluminum  oxides  by  burning  and  weighing 
the  precipitate  from  the  addition  of  ammonia.  If  it  is 
desired  to  separate  the  iron  from  the  aluminum  this  can 
be  done  by  dissolving  the  mixed  oxides  in  sulphuric  acid, 
reducing  with  zinc  and  titrating  with  permanganate. 

Magnesia  may  be  determined  in  the  filtrate  from  the 
lime  as  follows:  evaporate  in  an  acid  solution  to  about 
250  c.c.  add  about  25  c.c.  of  a  solution  of  microcosmic 
salts,  cool,  add  ammonia  drop  by  drop  with  constant  stir- 
ring until  slightly  ammoniacal;  add  about  one-half  the  vol- 
ume of  ammonia  and  let  stand  over  night;  filter  and  wash 
with  water  containing  ammonia  and  ammonium  nitrate. 
Ignite  and  weigh  as  magnesium  pyro-phosphate. 

BARYTES 

A  microscopic  examination  of  barytes  should  be  made 
to  determine  the  evenness  of  grinding,  the  size  and 
angularity  of  the  particles  and  whether  it  is  amorphous 
or  crystalline. 

The  only  determination  generally  necessary  for  barytes 
is  the  amount  of  insoluble  in  hydrochloric  acid.  This 
insoluble  can  generally  be  considered  barium  sulphate 
but  to  make  sure  that  there  is  no  silica  present,  it  is  al- 
ways well  to  evaporate  with  sulphuric  and  hydrofluoric 
acids. 

Natural  barytes  is  sometimes  contaminated  with  cal- 
cium fluoride.  Test  qualitativly  for  fluorides  by  moisten- 
ing with  water  in  a  platinum  dish,  adding  sulphuric  acid 


28         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

and  gently  heating.  The  top  of  the  dish  should  be 
covered  with  a  glass  coated  with  paraffine  with  several 
marks  scratched  through  to  the  glass.  If  fluorides  are 
present  the  glass  not  covered  by  the  paraffine  will  be 
etched.  If  there  is  any  amount  of  soluble  salts,  iron, 
aluminum,  lime,  etc.,  they  can  be  determined  in  the  nitrate 
from  the  insoluble  in  the  way  outlined  under  paris  white. 
If  lime  is  present  determine  the  soluble  sulphate  in  i  gram 
dissolved  in  hydrochloric  acid  and  filtered.  To  the 
boiling  filtrate  add  barium  chloride,  let  stand,  filter, 
ignite  and  weigh;  calculate  to  calcium  sulphate.  If 
there  is  any  lime  left  over  and  carbonates  are  present, 
calculate  the  remainder  to  calcium  carbonate,  unless 
the  presence  of  fluorides  is  detected. 

LITHOPONE 

Barium  Sulphate  and  Insoluble.  —  Dissolve  i  gram  in 
hydrochloric  acid,  adding  a  small  amount  of  potassium 
chlorate,  evaporate  to  about  one-half,  dilute  with  water, 
add  5  c.c.  dilute  sulphuric  acid,  boil,  allow  to  settle, 
filter,  ignite  and  weigh.  This  is  the  barium  sulphate 
and  insoluble. 

Total  Zinc  Oxide.  —  Heat  the  filtrate  to  boiling,  add 
sodium  carbonate  drop  by  drop  until  all  the  zinc  is  pre- 
cipitated as  carbonate,  filter  on  a  Gooch  crucible,  warm, 
ignite  and  weigh  as  zinc  oxide. 

Zinc  Sulphide.  —  Digest  i  gram  in  100  c.c.  of  i  per 
cent  acetic  acid  at  room  temperature  for  one-half  hour, 
filter  and  wash,  determine  zinc  in  filtrate  by  sodium 
carbonate.  The  difference  between  the  total  zinc  oxide 
and  the  zinc  oxide  soluble  in  acetic  acid,  multiplied  by 
1.1973  gives  the  zinc  present  as  sulphide. 


TESTING  OF  MATERIALS  29 

Barium  Carbonate.  —  Digest  2  grams  with  boiling 
dilute  hydrochloric  acid,  dilute  with  hot  water,  filter, 
and  determine  barium  in  the  filtrate  by  precipitation 
with  sulphuric  acid.  Figure  as  barium  carbonate. 

WHITE  LEAD 

Insoluble  and  Total  Lead.  —  Weigh  one  gram  of  the 
sample,  moisten  with  water,  dissolve  in  acetic  acid,  filter, 
wash,  ignite  and  weigh  the  insoluble.  To  filtrate  from 
insoluble  matter,  add  25  c.c.  sulphuric  acid  (i:  i),  evap- 
orate and  heat  until  acetic  acid  is  driven  off;  cool,  dilute 
to  200  c.c.  with  water,  let  stand  for  two  hours,  filter  on 
a  Gooch  crucible,  wash  with  i  per  cent  sulphuric  acid, 
ignite  at  low  heat  and  weigh  as  lead  sulphate. 

Carbon  Dioxide  and  Water.  —  In  determining  carbon 
dioxide  heat  i  gram  in  a  combustion  furnace,  catching 
the  water  in  a  calcium  chloride  tube  and  the  carbon 
dioxide  in  a  potash  bulb;  by  weighing  the  residue  left 
in  the  boat  the  exact  composition  can  be  calculated. 

Calculate  the  carbon  dioxide  to  lead  carbonate,  sub- 
tract the  lead  oxide  necessary  to  form  the  carbonate 
from  the  total  lead  oxide  present  and  calculate  the  re- 
maining lead  oxide  to  lead  hydroxide.  Calculate  the 
water  necessary  for  the  lead  hydroxide  and  subtract 
it  from  the  total  water  and  the  remaining  water  can  be 
reported  as  moisture. 

In  determining  carbon  dioxide  the  method  in  most 
common  use  now  is  to  pass  the  evolved  gas  through  a 
solution  of  barium  hydroxide,  filter  as  rapidly  as  possi- 
ble with  the  greatest  exclusion  of  air  liable  to  contain 
carbon  dioxide,  wash  in  boiling  water,  dissolve  in  hydro- 
chloric acid  and  determine  as  barium  sulphate.  Cal- 


30         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

culate  the  amount  of  carbon  dioxide  from  the  barium 
sulphate. 

CALCIUM  SULPHATE 

Determine  sulphate  by  precipitation  with  barium  chlo- 
ride as  described  under  barytes. 

In  another  portion  determine  insoluble  and  in  the 
nitrate  from  the  insoluble  determine  lime  by  precipita- 
tion with  ammonium  oxalate. 

ZINC  OXIDE 

Determine  zinc,  after  solution,  as  carbonate,  as  de- 
scribed under  lithopone. 

CHROMIUM  COLORS 
Chrome    Yellow,  Chrome  Orange,  Chrome  Red 

A  microscopic  examination  will  show  the  character 
of  the  pigment,  whether  it  is  crystalline  or  amorphous. 

Dissolve  .5  gram  in  hydrochloric  acid,  filter  off  insolu- 
ble, dilute  the  filtrate  to  400  c.c.,  almost  neutralize  with 
ammonia,  pass  in  a  rapid  stream  of  hydrogen  sulphide 
until  all  the  lead  is  precipitated  as  lead  sulphide,  filter, 
wash  with  water  containing  some  hydrogen  sulphide, 
dissolve  the  lead  in  dilute  nitric  acid,  add  an  excess  of 
sulphuric  acid,  heat  to  fuming  and  determine  the  lead 
as  sulphate  in  the  usual  way. 

Chromium.  —  Evaporate  the  filtrate  from  the  lead 
sulphide  to  small  bulk,  add  ammonia  to  excess,  boil  until 
the  pink  color  disappears,  filter,  wash  with  hot  water, 
ignite  and  weigh  as  chromium  oxide. 

Sulphate.  —  Weigh  one  gram,  dissolve  in  hydrochloric 
acid,  dilute  considerably  and  determine  the  sulphate  by 
precipitation  with  barium  in  the  usual  way. 


TESTING  OF  MATERIALS  31 

Chrome  Green 

A  microscopic  examination  will  show  the  character 
of  the  particles  and  also  if  it  is  a  dry  mixture  or  made 
by  simultaneous  precipitation.  A  badly  made  green 
will  show  yellow  and  blue  as  well  as  green,  while  a  well 
made  green  will  show  green  and  some  blue  but  no  yellow. 

The  analysis  of  the  green  is  carried  on  in  the  same 
way  as  for  chrome  yellow  except  that  the  sample  is 
first  gently  ignited  in  a  porcelain  crucible  to  decom- 
pose the  blue. 

The  precipitate  with  ammonium  hydroxide  also  con- 
tains iron  besides  the  chromium,  and  it  is  necessary  to 
dissolve  this  precipitate  with  hydrochloric  acid  on  the 
filter  and  make  it  up  to  a  definite  volume.  One  part 
of  this  is  taken  and  sodium  peroxide  added  in  suffi- 
cient amount  to  render  the  solution  alkaline  and  to 
oxidize  to  chromate,  boil  until  all  of  the  hydrogen  per- 
oxide is  driven  off,  cool,  make  acid  with  sulphuric  acid, 
add  a  measured  excess  of  standard  ferrous  sulphate  and 
titrate  the  excess  of  iron  with  standard  potassium 
bichromate. 

Determine  iron  in  another  portion  by  reduction  and 
titration  with  potassium  permanganate. 

VERMILLION 

About  the  most  satisfactory  way  to  determine  the 
purity  of  vermillion  is  to  ash  one  gram  of  the  pigment. 
Not  more  than  .5  per  cent  should  remain. 

Vermillion  should  also  be  tested  for  dye  toners  by  being 
shaken  with  alcohol,  chloroform  and  hot  water  and  filtered. 
If  the  filtrate  shows  color  it  is  an  indication  of  dye. 


32         CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 

IRON  OXIDE  AND  EARTH  PIGMENTS 

It  is  seldom  necessary  to  analyze  these  pigments  but 
when  it  is  the  iron  and  insoluble  can  be  determined  in 
the  usual  way. 

Manganese.  —  For  those  pigments  that  contain  man- 
ganese, dissolve  .2  gram  in  nitric  acid  with  heat  and  add 
75  c.c.  of  strong  nitric  acid,  boil  and  add  5  grams  po- 
tassium chlorate,  heat  to  boiling,  add  50  c.c.  more  strong 
nitric  acid  and  a  little  more  potassium  chlorate,  boil 
until  fumes  cease  to  come  off,  cool,  filter  on  asbestos 
and  wash  with  strong  nitric  acid,  suck  dry  and  wash 
out  the  remaining  nitric  acid  with  water,  transfer  pre- 
cipitate and  asbestos  to  a  beaker,  add  a  measured  excess 
of  standard  ferrous  sulphate  in  dilute  sulphuric  acid,  stir 
until  all  the  manganese  dioxide  is  dissolved  and  titrate  the 
remaining  ferrous  sulphate  with  potassium  permanganate. 
A  ferrous  solution  of  the  proper  strength  is  made  by 
dissolving  10  grams  of  crystallized  ferrous  sulphate  in 
900  c.c.  of  water  and  100  c.c.  of  sulphuric  acid. 

FERROCYANIDE  BLUES 
Prussian  Blue,   Bronze  Blue,  Chinese  Blue 

Insoluble.  —  Ignite  one  gram  in  a  porcelain  crucible 
at  a  low  temperature,  add  25  c.c.  strong  hydrochloric 
acid,  boil  until  all  the  iron  is  decomposed,  add  water, 
bring  to  a  boil  again  and  filter,  wash  with  hot  water, 
ignite  and  weigh  the  insoluble. 

Iron. —  Make  up  filtrate  to  volume  and  in  an  aliquot 
part  determine  iron  by  reduction  with  zinc  and  titration 
with  potassium  permanganate. 

Aluminum. —  In  another  portion  the  iron  and  alumi- 


TESTING  OF  MATERIALS  33 

num  oxides  may  be  precipitated  with  ammonia  and  the 
aluminum  found  by  difference  from  the  total  oxides 
and  the  amount  of  iron  found  by  titration. 

Dyes.  —  It  is  well  also  to  test  the  blues  for  dye  toners 
by  shaking  them  up  in  the  various  solvents.  This 
should  be  very  carefully  done  as  it  is  sometimes  very 
difficult  to  filter  out  the  blue  due  to  the  formation  of  a 
colloidal  solution.  This  is  frequently  taken  to  be  a  dye 
but  in  reality  is  the  blue  itself. 

ULTRAMARINE  BLUE 

An  analysis  of  ultramarine  blue  is  of  very  little  value. 
The  principal  determinations  are,  however,  aluminum, 
silica,  soda,  total  sulphur,  sulphur  as  sulphate  and  sul- 
phur as  sulphide. 

Silica.  —  Silica  is  determined  by  solution,  evaporation 
to  dryness,  resolution  and  filtration,  the  residue  being 
ignited  and  weighed. 

Aluminum. — Aluminum  is  determined  in  the  filtrate  from 
the  silica  by  precipitation  with  ammonium  hydroxide. 

Soda.  —  Soda  is  determined  in  the  filtrate  from  the 
aluminum  by  adding  sulphuric  acid,  evaporating  to  dry- 
ness  and  weighing  as  sodium  sulphate. 

Total  Sulphur.  —  Mix  i  gram  of  pigment  with  4  grams 
of  sodium  carbonate  and  4  grams  of  sodium  peroxide  in 
a  nickel  crucible,  cover  with  about  a  gram  of  sodium 
carbonate,  fuse,  using  an  asbestos  shield  to  prevent  the 
sulphur  from  being  taken  up  from  the  gas;  dissolve  the 
fused  mass  in  water,  make  acid  with  hydrochloric  acid, 
precipitate  with  barium  chloride  and  weigh  as  barium 
sulphate. 

Sulphur  as  Sulphate.  —  Dissolve  one  gram  in  hydro- 


34         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

chloric  acid,  boil  till  hydrogen  sulphide  is  driven  off, 
add  barium  chloride  and  weigh  as  barium  sulphate. 
Subtract  sulphur  as  sulphate  from  total  sulphur  and 
remainder  is  sulphur  as  sulphide. 

ORANGE  MINERAL 

Dissolve  .25  gram  of  sample  in  50  c.c.  of  a  solution 
containing  1000  c.c.  water,  126  c.c.  nitric  acid  and  600  c.c. 
one-fifth  normal  oxalic  acid.  Then  add  25  c.c.  of  25  per 
cent  sulphuric  acid  and  titrate  with  permanganate;  run 
a  blank  and  calculate  the  difference  to  lead  dioxide. 

BLACKS 

Total  Ash.  —  Weigh  one  gram  into  a  platinum  dish  and 
burn  off  carbon  at  a  very  low  temperature. 

Insoluble  Ash.  —  Transfer  total  ash  to  beaker,  moisten 
with  water,  add  25  c.c.  strong  hydrochloric  acid,  boil  for 
fifteen  minutes,  dilute  with  water,  bring  to  boil  again, 
filter  off  insoluble,  wash  with  hot  water  and  weigh  after 
ignition. 

ANALYSIS  or  SOLUBLE  ASH 

Phosphates.  —  Make  up  filtrate  from  insoluble  matter 
to  500  c.c.,  if  phosphates  are  present,  draw  off  an  aliquot 
portion,  make  alkaline  with  ammonia  and  acid  with  nitric 
acid,  heat  the  solution  on  a  water  bath  to  60°  C.  add 
50  c.c.  molybdate  solution,  heating  at  this  temperature 
for  one  hour,  filter  and  wash  with  a  wash  solution  contain- 
ing nitric  acid,  ammonium  nitrate  and  a  small  amount  of 
molybdate  solution  about  three  times.  Dissolve  the 
precipitate  on  the  filter  with  ammonia,  allowing  the  solu- 
tion to  run  into  the  original  beaker.  Precipitate  with 


TESTING  OF  MATERIALS  35 

hydrochloric  acid  and  add  ammonia  in  slight  excess  to 
redissolve  the  precipitate,  cool,  add  10  c.c.  magnesia 
mixture  and  about  one-half  the  volume  of  ammonia,  stir, 
allow  to  stand  over  night,  filter,  wash  with  solution  con- 
taining one  part  ammonia  and  three  parts  water,  ignite, 
weigh  and  calculate  to  phosphoric  anhydride. 

Lime.  —  To  another  portion  of  the  original  solution 
add  ammonia  to  alkalinity  and  make  acid  with  acetic 
acid,  filter,  wash  with  hot  water,  boil  the  filtrate  and  add 
boiling  ammonium  oxalate,  boil  for  a  few  minutes  longer, 
allow  to  settle,  filter,  wash  with  hot  water  and  weigh, 
after  blasting,  as  calcium  oxide. 

Sulphates.  —  Determine  sulphates  in  another  portion 
with  barium  chloride. 

Iron.  —  Take  another  portion  of  the  original  solution 
and  add  15  c.c.  of  dilute  sulphuric  acid,  evaporate  to 
expel  hydrochloric  acid,  take  up  with  water,  reduce  with 
zinc  and  titrate  with  permanganate.  When  the  black 
does  not  contain  phosphates  determine  lime,  iron  and 
sulphates  in  the  usual  way. 

Blacks  are  occasionally  toned  with  prussian  blue,  and 
to  determine  this  boil  the  sample  with  a  4  per  cent  solu- 
tion of  sodium  hydroxide,  filter,  make  acid  with  hydro- 
chloric acid  and  add  a  solution  containing  a  mixture  of 
ferrous  and  ferric  chloride  or  sulphate.  A  blue  precipitate 
indicates  the  presence  of  prussian  blue. 

ORGANIC  LAKES 

The  only  available  schemes  for  identifying  the  aniline 
dyes  used  in  lake  pigments  are  much  too  complicated  to 
be  gone  into  in  this  volume.  However  the  book  entitled 
"Tests  for  Coal  Tar  Colors  in  Aniline  Lakes"  by  George 


36         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Zerr  and  Dr.  C.  Mayer  will  be  found  to  be  a  great  aid 
in  the  examination  of  lake  pigments. 

SECTION  THREE.     PHYSICAL  TESTS  OF 
PIGMENTS 

Color  Strength.  —  .2  gram  of  the  standard  pigment 
and  one  gram  of  zinc  white  are  weighed  out  accurately 
on  an  analytical  balance  and  a  like  quantity  of  the  pig- 
ment to  be  tested  and  zinc  white  is  also  weighed.  Trans- 
fer these  materials  to  a  marble  slab  and  add  drop  by  drop 
sufficient  oil  to  the  standard  to  make  it  into  a  stiff  paste. 
Add  the  same  number  of  drops  to  the  sample  to  be  tested, 
mix  both  piles  separately  and  thoroughly  with  a  palette 
knife  and  rub  each  one  50  times  with  the  muller  de- 
scribed under  laboratory  apparatus.  Each  rub-out  is 
then  gathered  up  with  a  palette  knife  and  rubbed  again 
25  times.  After  this  final  rubbing  each  sample  is  gathered 
together  on  the  slab  and  a  small  amount  of  each  is  put  side 
by  side  on  a  glass.  If  the  sample  shows  weaker  than  the 
standard  it  is  weighed  out  again  with  the  same  amount  of 
zinc  white  and  a  little  more  color  and  the  rubbing  is  re- 
peated. This  is  done  until  the  sample,  with  the  color  added, 
exactly  matches  the  standard.  Thus,  if  for  .2  gram  of 
the  standard  it  takes  .25  grams  of  the  sample  to  make  a 
match,  the  sample  is  called  5  per  cent  weak;  if,  on  the 
other  hand,  the  sample  being  tested  shows  stronger  than 
the  standard,  zinc  white  is  added  to  reduce  the  color  to 
a  match  and  the  sample  is  said  to  be  strong. 

The  authors  have  failed  to  get  satisfactory  results  by 
using  a  greater  amount  of  white  as  the  difference  in  the 
strength  is  not  so  apparent  under  these  circumstances 
as  when  a  greater  amount  of  color  is  used  as  recommended 


TESTING  OF  MATERIALS  37 

above.  The  use  of  chrome  green  or  prussian  blue  with 
yellows  has  also  been  found  not  to  give  as  satisfactory 
and  uniform  results  as  the  use  of  white. 

Where  colors  differ  greatly  in  hue,  judgment  must  be 
used  in  estimating  their  weakness  or  strength  as  it  is 
impossible  to  get  two  pigments  of  the  same  color  that 
differ  in  hue  to  look  alike,  and  often  this  variation  in  hue 
is  taken  for  weakness  in  color  strength. 

Fineness.  —  Fineness  can  be  tested  by  the  use  of  sieves 
of  very  fine  mesh  or  bolting  cloth,  but  as  printing  inks 
require  colors  of  a  great  degree  of  fineness  it  is  more 
satisfactory  to  judge  the  fineness  by  rubbing  the  pigment 
under  the  finger  on  a  smooth  piece  of  paper.  After  a 
little  experience  the  fineness  of  a  pigment  can  be  easily 
judged  by  this  method. 

In  some  cases  the  microscope  is  of  value  in  determining 
fineness. 

Top  Hue  and  Under  Hue.  —  Weigh  out  one  gram  each 
of  the  sample  and  standard  and  add  the  same  amount 
of  oil  to  each,  mix  with  a  palette  knife  and  rub  each 
50  times  with  a  muller.  Compare  the  top  hues  on 
glass.  Then  take  some  of  the  material  and  rub  it  out 
on  a  piece  of  paper  side  by  side  with  the  standard. 
Where  the  color  is  rubbed  out  thin  the  under  hue  will 
show  up. 

Bleeding  in  Oil.  —  Allow  the  paper  with  the  rub-outs 
for  under  hue  to  hang  for  a  day  and  if  the  oil  that  sepa- 
rates out  is  colored,  the  pigment  is  soluble  in  the  oil  and 
will  bleed.  This  bleeding  should  be  compared  with  the 
standard. 

A  pigment  that  bleeds  in  oil  to  any  great  extent  should 
not  be  used  in  printing  inks  as  it  will  strike  through  the 


38         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

paper  and  stain  the  other  side,  penetrate  through  a 
color  laid  over  it  or  spread  from  the  lines  and  give  the 
work  a  dirty  look. 

Bleeding  in  Water.  —  Weigh  one  gram  of  the  sample 
into  an  Erlenmeyer  flask,  shake  up  with  100  c.c.  of  dis- 
tilled water,  filter  through  a  filter  paper  into  a  test  tube 
and  if  the  filtrate  is  colored  the  material  bleeds  in  water. 

The  degree  of  this  bleeding  should  not  be  very  great 
as  it  shows  either  that  the  coloring  matter  in  the  lake  is 
soluble  or  that  it  is  imperfectly  fixed  on  the  base,  and 
this  condition  is  apt  to  cause  trouble  in  classes  of  work 
where  the  paper  is  used  wet  or  is  liable  to  come  in 
contact  with  water. 


PART   TWO 

MANUFACTURE  AND   PROPERTIES   OF  INK-MAKING 
MATERIALS 

SECTION   ONE.     DRY  COLORS 
1.     REDS 

VERMILLION 

VERMILLION  is  the  red  sulphide  of  mercury  HgS.  There 
are  two  forms  of  HgS,  the  black  sulphide,  which  is  amor- 
phous and  the  red  sulphide  which  is  crystalline.  Ver- 
million,  under  the  name  of  "Cinnabar"  occurs  in  a  great 
many  places  but  natural  vermillion,  at  present,  is  not 
found  on  the  market  as  a  pigment,  as  the  artificial  ver- 
million is  its  superior  in  color  and  brightness. 

The  manufactured  vermillion  on  the  market  today  is 
mostly  made  by  the  following  process: 

When  metallic  mercury  is  mixed  with  a  concentrated 
solution  of  potassium  pentasulphide  at  a  moderate  tem- 
perature a  dark  red  powder  is  obtained,  which  is  con- 
verted by  a  concentrated  solution  of  caustic  potash  into 
bright  red  vermillion.  As  the  color  approaches  bright 
redness  great  care  must  be  taken  as  too  high  a  tempera- 
ture will  produce  a  dull  red  of  brown  hue.  The  material 
is  then  washed  with  dilute  caustic  potash  and  after- 
wards with  water,  until  the  alkaline  reaction  disappears. 


40         CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 
PROPERTIES  or  VERMILLION 


Top  Hue 

Under  Hue 

Fineness 

Bright  red. 

Red  of  orange  hue. 

Not  very  fine. 
Lightens  on  grinding. 

Flow 

Incompatibility 

Abrasive  Qualities 

Being   heavy   bodied    it 
does  not  make  an  ink  that 
flows  well. 

Cannot  be  used  with  pig- 
ments containing  lead. 

Not  abrasive. 

Oil  Absorption 

Bleeding 

Fastness  to  Light 

Requires    only    a    small 
quantity  of  oil. 

Does  not  bleed.     When 
toned  with  dye  toners  will 
bleed  in  alcohol  and  other 
solvents. 

Fast    to    light    unless 
toned  with  dye  toners. 

Shortness 

Drying 

Smoothness 

Somewhat  short. 

Poor     drying     pigment. 
Will  rub  off  even  after  a 
long  time. 

Does  not  make  a  smooth 
ink  particularly  for  typo- 
graphic work. 

Behavior  towards 
Vehicles 

Atmospheric  Influences 

Works  up  well  but  sepa- 
rates on  standing. 
It  also  has  a  tendency  to 
stand  up  from  the  vehicle 
when  printed,  the  latter  go- 
ing into  the  paper. 

Will  turn  brown  after  exposure  to  air.     The  most 
widely  held  theory  is  that  it  gradually  reverts  to  the 
amorphous  condition,  that  is  to  the  black  sulphide, 
although  this  theory  is  by  no  means  proven.     This 
seems  however  to  be  substantiated  by  the  fact  that 
the  red  brown-hued  pigment  is  produced  when  too 
much  heat  is  used.     The  same  hue  is  produced  when 
an  ink  containing  vermillion  is  subjected  to  prolonged 
grinding. 
The  chemical  composition  of  the  two  forms  is  the 
same. 

PROPERTIES  OF  INK-MAKING  MATERIALS 


PROPERTIES  OF  VERMILLION  —  Continued 


Value  as  an  ink-making 
pigment 


Vermillion  is  not  a  very  good  pigment  to  use  in 
printing  inks.  It  is  high  priced  and  does  not  work 
well  as  a  typographic  ink  for  the  following  reasons: 
it  prints  out  unevenly  on  account  of  its  shortness 
and  being  a  poor  drier  it  is  liable  to  rub  off  and 
offset.  Being  a  heavy  pigment  it  separates  out  of 
the  vehicle  requiring  remixing  after  standing  a  little 
while.  For  plate  printing  it  works  fairly  well  but  is 
not  of  much  value  on  account  of  its  rubbing  off,  due 
to  lack  of  drying,  separation  on  standing  and  its  ten- 
dency to  darken. 

There  are  many  lake  colors  that  can  be  used  in 
all  cases  requiring  vermillion  of  lower  cost,  and  that 
will  give  better  working  results  for  all  classes  of 
work. 


2.     BLUES 

FERROCYANIDE  BLUES 

This  type  of  blue  comprises  those  pigments  known  as 
Prussian  blue,  Chinese  blue  and  bronze  blue.  They  are 
all  of  practically  the  same  chemical  composition,  namely 
ferric-ferrocyanide  [Fe4(FeCN6)3].  This  formula  is  how- 
ever only  theoretical  as  the  commercial  pigment  varies 
according  to  the  method  of  manufacture  and  it  is  ex- 
tremely doubtful  if  it  is  ever  of  the  above  composition 
exactly. 

Broadly  the  manufacture  of  these  blues  depends  on 
the  mixture  of  a  ferrous  salt,  usually  ferrous  sulphate 
(copperas),  with  potassium  ferrocyanide  (yellow  prussiate 
of  potash)  and  the  oxidation  of  the  ferrous  iron  to  ferric 
iron  by  a  powerful  oxidizing  agent.  These  three  varieties 
of  ferrocyanide  blues,  while  they  have  the  same  approx- 
imate chemical  composition,  differ  from  each  other 


42         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

slightly  in  this  and  to  somewhat  a  greater  extent  in 
physical  characteristics.  This  variation  is  due  to  differ- 
ences in  the  formula  brought  about  by  differences  in  the 
manufacture.  These  modifications  will  therefore  be  taken 
up  in  order. 

A.  Prussian  Blue.  —  This  is  the  darkest  variety  of 
ferrocyanide  blue  and  has  a  decided  red  hue.     For  mak- 
ing a  soft-drying  prussian  blue  of  good  red  hue  the  fol- 
lowing process  will  be  found  satisfactory. 

Solution  No.  1    468  Ibs.  Potassium  Ferrocyanide 

2  344    "    Ferrous  Sulphate 

(dissolved  in  the  same  amount  of  water) 

3  110  Ibs.  66°  Be  Sulphuric  Acid 

4  850    "    35°  Be  Commercial  Nitrate  of  Iron 

5  44    "    Sulphate  of  Aluminum  in  water 

6  112    "    Sodium  Carbonate  in  water 

Heat  solutions  No.  i  and  No.  2  to  boiling  and  run  simul- 
taneously into  a  tub  of  boiling  water  with  constant  stir- 
ring. When  precipitation  is  complete  add  solutions  No.  3 
and  No.  4,  boil  until  oxidation  is  complete,  wash  free  from 
iron  and  add  No.  5  followed  by  No.  6;  filter  without 
washing  and  dry  at  160°  F.  The  filtrate  contains  about 
25  pounds  of  blue  as  sodium  ferrocyanide,  which  can  be 
obtained  by  acidifying,  precipitating  with  ferrous  sul- 
phate and  oxidizing  with  commercial  nitrate  of  iron. 
This  gives  a  good  pigment  at  moderate  cost. 

B.  Chinese  Blue.  —  This  is  a  light  variety  of  ferro- 
cyanide blue  with  somewhat  of  a  green  hue.     Its  method 
of  manufacture  is  similar  to  prussian  blue  as  described 
before,   only  it  is  oxidized  with  hydrochloric  acid  and 
potassium  chlorate  without  the  final  addition  of  alkali. 

A  bright  Chinese  blue  is  produced  as  follows: 


PROPERTIES  OF  INK-MAKING  MATERIALS  43 

70    Ibs.  Yellow  Prussiate  of  Potash 


Solution  No.  1  >  ....      ,   TT    ,      , ,    .    .   .,  orv0  m 
(17      ''    Hydrochloric  Acid  20   Be 

2  45      "    Ferrous  Chloride  35°  Be 

3  f  10i    "    Hydrochloric  Acid  20°  Be 
\  10£    "    Potassium  Chlorate 

Boil  solution  No.  i  till  it  is  neutral  and  then  run  it  and 
the  45  pounds  of  solution  No.  2  heated  to  boiling  into  a 
tub  of  boiling  water  adding  simultaneously  solution  No.  3, 
boil  with  steam  until  oxidation  is  complete,  wash  with 
water  and  filter. 

C.  Bronze  Blue.  —  This  is  a  variety  of  ferrocyanide 
blue  that  shows  a  metallic  luster  on  drying.  It  can  be 
made  by  the  following  formula: 

Solution  No.  1  400  Ibs.  Yellow  Prussiate  of  Potash  in  water 

2  400    "    Ferrous  Sulphate  in  water 

3  136    "    36°  B6  Nitric  Acid 

4  144    "    66°  Be  Sulphuric  Acid 

Heat  solutions  No.  i  and  No.  2  to  boiling  and  run  them 
simultaneously  into  a  tub  of  boiling  water;  run  in  solu- 
tions No.  3  and  No.  4,  boil  the  entire  solution  till  oxida- 
tion is  complete,  wash  once  and  filter.  This  makes  a 
brilliant  blue  of  strong  bronze  hue. 


ULTRAMARINE  BLUE 

Ultramarine  blue  is  made  from  a  mixture  of  aluminum 
silicate,  sodium  carbonate,  sodium  sulphate  and  charcoal. 
This  is  calcined  in  a  crucible  and  ground.  The  propor- 
tions vary  as  regards  the  hue  to  be  produced  and  it  is 
very  difficult  to  match  a  given  hue.  As  the  formula  for 
a  given  hue  depends  on  the  composition  of  the  raw  ma- 
terials no  attempt  to  give  formulas  will  be  made. 


44         CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 
PROPERTIES  OF  THE  BLUES 


Name 

Top  Hue 

Under  Hue 

Fineness 

Ultramarine 

Fairly  dark 

Fairly  light  blue 

Very  fine  impalpable 

blue. 

blue. 

of  red  hue. 

powder. 

Prussian 

Dark  blue. 

Blue  of  red  hue. 

The  ferrocyanide  blues  can 

blue. 

be  either  soft  or  hard  depend- 

ing on  the  method  of  manu- 

Chinese 
blue. 

Dark  blue. 

Blue  of  green  hue. 

facture  and  the  process  of  dry- 
ing.    The  best  of  these  blues 

Dark  blue 

are  the  ones  that  have  been 

Bronze 
blue. 

bronze  tone 
in  light. 

Blue  of  green  hue. 

dried  soft  and  feel  velvety  to 
the  touch. 

Name 

Drying 

Shortness 

Flow 

Ultramarine 
blue. 

Does  not  dry  well. 
Has    a    tendency    to 
rub  off. 

Is  not  short. 

Flows  well.  Rather  long 
in  litho-varnish. 

blue 

Ferrocyanide  blues 

Fairly  short. 

dry  well.    They  exert 

Chinese 
blue. 

a  slight  drying  action 
themselves    but    not 
enough  to  make  them 

Not  short. 

All  the  ferrocyanide 
blues  flow  well. 

harden  in  the  foun- 

blue. 

tain  or  the  package. 

Not  short. 

Name 

Oil  Absorption 

Smoothness 

Fastness  to  light 

Ultramarine 
blue. 

Rather  low. 

Makes  a  smooth 
ink. 

Fast  to  light. 

Prussian 

Good. 

Bronze 
blue. 

Good. 

All  ferrocyanide 
blues  make  smooth 

All     the     ferrocyanide 
blues  are  fast  to  light. 

Chinese 

Good. 

blue. 

PROPERTIES  OF  INK-MAKING  MATERIALS 
PROPERTIES  OF  THE  BLUES  —  Continued 


45 


Name 

Atmospheric 
Influences 

Incompatibility 

Value  as  an  Ink-making 
Pigment 

Ultramarine 

Darkens  somewhat 

Cannot     be 

Fair  on  account  of  its 

blue. 

on  exposure. 

mixed  with  lead 

poor  working  qualities  on 

colors. 

the  press  and  its  lack  of 

distribution. 

Makes  a  tacky  ink  with 

varnish  and  has  a  tendency 

to  print  out  unevenly. 

Rubs  off  somewhat  after 

drying. 

Prussian 
blue. 

Chinese 
blue. 

Bronze 
blue. 

All  the  f  errocyanide 
blues  turn  green  on 
exposure  to  the  at- 
mosphere due  to  oxi- 
dation. 

The      ferrocya- 
nide  blues  should 
not  be  mixed  with 
paris  white  as  they 
decompose  it. 
For  this  reason 
they     should     be 
mixed     on      a 
straight      barytes 
base. 

With  the  exception  of 
their  change  of  hue  on  ex- 
posure these  blues  make 
first-class  printing  inks  and 
are    especially    good    for 
toning  blacks. 
On  account  of  price  and 
their  deep  blue  color  there 
are  no  pigments  that  can 
really  take  their  place. 

3.  YELLOWS 

CHROME  YELLOWS 

These  pigments,  without  doubt  the  most  important 
and  most  used  mineral  pigments,  are  divided  into  three 
classes  although  they  do  vary  from  a  light  canary  yellow 
through  every  hue  of  this  color  to  a  red  of  orange  hue. 
It  is  customary,  however,  to  class  all  chromate  of  lead 
yellows  as  either  chrome  yellows,  chrome  yellow  of  orange 
hue  or  chrome  yellow  of  red  hue  and  to  consider  the 
different  modifications  as  hues  of  these  three. 


46         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

In  this  chapter  the  first-class  or  chrome  yellows  will  be 
taken  up,  the  other  varieties  being  treated  under  the  head 
of  oranges.  The  chrome  yellows  are  all  essentially  the 
normal  chromate  of  lead  of  the  formula  PbCrO4,  the 
different  hues  being  produced  by  different  processes  of 
manufacture,  by  which  varying  amounts  of  lead  sul- 
phate or  carbonate  are  introduced  and  different  condi- 
tions of  physical  structure  are  produced.  Thus  the  more 
lead  sulphate  or  carbonate  present  in  the  finished  product 
the  lighter  the  pigment  produced  will  be.  Different 
effects  will  also  be  produced  depending  on  the  size  and 
character  of  the  crystallization.  The  more  crystalline 
the  product  is  the  darker  it  will  be  and  the  less  will  be 
its  color  strength. 

Beginning  with  chrome  yellow,  which  is  the  normal 
chromate  of  lead,  PbCrO4,  we  will  therefore  find  a  number 
of  chrome  yellows  of  slightly  different  hue,  growing  lighter 
as  the  amount  of  simultaneously  precipitated  lead  sul- 
phate or  unused  lead  carbonate  where  white  lead  is  used 
as  a  source  of  lead,  increases. 

In  the  manufacture  of  these  chrome  yellows  care  must 
be  taken  to  precipitate  the  color  in  as  nearly  the  amor- 
phous condition  as  possible  to  insure  the  proper  amount 
of  color  strength.  This  can  be  done  by  precipitating  the 
pigment  in  a  very  dilute,  cold,  solution,  with  constant 
stirring.  The  washing  should  be  done  as  rapidly  as  pos- 
sible and  the  lead  and  chromate  solutions  should  be  run 
into  the  tub  simultaneously.  In  order  to  exactly  dupli- 
cate a  hue,  care  should  be  taken  that  the  same  strength 
of  solution,  amount  of  water,  stirring  and  temperature  is 
used  every  time.  If  this  is  attended  to  the  results  of  many 
different  batches  will  duplicate  each  other  very  closely. 


PROPERTIES  OF  INK-MAKING  MATERIALS  47 

Chrome  yellows  of  different  hues  are  found  that  con- 
tain white  lead  instead  of  sulphate  of  lead  or  mixtures 
of  white  lead  and  sulphate  of  lead  but  the  authors  have 
found  after  a  long  series  of  tests  that  the  chrome  yellows 
which  contain  lead  sulphate  show  the  least  darkening  on 
exposure  and  have  better  working  qualities. 

A.  Chrome  Yellow.  —  This  is  the  darkest  form  of  the 
chrome  yellows.  It  is  the  normal  chromate  of  lead  and 
has  a  slight  orange  hue. 

For  the  production  of  a  chrome  yellow  of  a  good  deep 
yellow  with  a  slight  orange  hue  and  of  good  color  strength 
and  of  great  softness  the  following  formula  will  be  found 
satisfactory: 

Solution  No.  1      100  Ibs.  Lead  Nitrate  to  600  Ibs.  water  @  50°  F. 

2  35    "    Sodium  Bichromate  to  600  Ibs.  water  ©  50°  F. 

3  2000   "    Water  @  50°  F. 

Run  No.  i  and  No.  2  simultaneously  into  No.  3  with 
constant  stirring,  let  settle,  wash  and  dry  in  vacuum  or 
at  about  160°  F.  As  is  seen  from  the  above  formula  the 
lead  should  be  somewhat  in  excess. 

Between  the  chrome  yellow  mentioned  above  and 
chrome  yellow  of  orange  hue  there  are  a  variety  of  yellows 
of  increasing  red  hue  that  are  produced  by  the  action  of 
sodium  or  potassium  bichromate  and  monochromate  on 
basic  lead  acetate.  The  general  way  of  producing  this 
effect,  which  is  the  production  of  a  certain  small  amount 
of  basic  lead  chromate  along  with  the  normal  lead  chro- 
mate, is  to  neutralize  the  bichromate  with  an  alkaline 
carbonate;  thus  converting  part  of  the  salt  into  the 
monochromate.  These  colors  being  mixtures  of  basic 
lead  chromate  and  normal  lead  chromate  should  not 
rightfully  be  classed  as  chrome  yellows,  but  they  are  not 


48         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

red  enough  in  hue  to  be  considered  as  oranges  to  which 
class  by  chemical  composition  they  really  belong. 

B.  Chrome  Yellow  Lemon.  —  This  is  the  lightest  of 
the  chrome  yellows  and  has  a  slight  green  hue.  It  is 
variously  referred  to  as  primrose  yellow,  lemon  yellow 
and  canary  yellow,  depending  on  the  lightness  of  the  hue. 
It  is  a  mixture  of  normal  lead  chromate  and  sulphate  or 
carbonate  of  lead.  The  chrome  yellow  lemon  made  from 
white  lead  is  not  as  stable  to  light  and  has  not  the  work- 
ing qualities  for  printing  inks  that  the  straight  sulpho- 
chromates  have  and  it  is  preferable  in  the  ink-making 
business  to  have  a  light  yellow  made  with  the  sulphate 
alone. 

A  formula  for  making  a  lemon  hued  yellow  of  good 
color  strength,  brillancy  and  fastness  to  both  light  and 
atmosphere  is  as  follows: 

Solution  No.  1    100  Ibs.  Lead  Nitrate  to  600  Ibs.  water  at  50°  F. 

2  25    "    Sodium  Bichromate  to  250  Ibs.  water  @  50°  F. 

3  35    "    Sodium  Sulphate  to  250  Ibs.  water  @  50°^F. 

4  Mix  solutions  No.  2  and  No.  3 

5  2000  Ibs.  water  at  50°  F. 

Run  solutions  No.  i  and  No.  4  simultaneously,  with  con- 
stant stirring,  into  solution  No.  5,  wash  well  with  water 
and  dry  at  about  100°  F. 

As  stated  before  a  whole  series  of  hues  can  be  produced 
between  chrome  yellow  and  chrome  yellow  lemon  hue 
by  varying  the  amounts  of  bichromate  and  sodium  sul- 
phate or  lead  carbonate. 

All  lemon  hued  yellows  have  a  tendency  to  darken  in 
hue  after  being  made.  This  difficulty  can  be  overcome 
by  adding  a  slight  excess  of  sodium  carbonate  over 
the  amount  necessary  to  neutralize  the  acid  set  free  in  the 
above  process  and  taking  up  any  excess  of  soda  by  the 


PROPERTIES  OF  INK-MAKING  MATERIALS  49 

addition  of  calcium  chloride  or  by  neutralizing  the  acid 
with  freshly  precipitated  hydrate  of  alumina.  For  the 
above  formula  7  pounds  of  calcium  chloride  40°  Be  and 
12  pounds  sodium  carbonate  added  immediately  after 
the  precipitation  of  the  chromate  will  be  found  satis- 
factory. This  method  of  procedure  explains  why  small 
amounts  of  calcium  carbonate  or  alumina  are  found  in  a 
great  many  chrome  yellow  lemons. 

The  lightest  chrome  yellow  lemons,  the  so-called  sul- 
phur or  canary  yellows,  that  have  a  very  green  under  hue 
are  produced  by  adding  citric  or  tartaric  acid  to  the  bi- 
chromate solution  along  with  the  sodium  sulphate.  Some 
color  makers  hold  the  theory  that  the  yellow  pigments 
thus  made  will  not  darken  on  exposure  to  sunlight,  but 
we  have  found  that  this  is  not  the  case,  in  fact  pigments 
made  with  the  citrate  or  tartrate  of  lead  showed  more 
darkening  on  exposure  than  those  made  with  the  straight 
sulphate. 

The  reason  why  a  chrome  yellow  made  in  a  very  cold 
solution  or  with  an  excess  of  lead  sulphate  should  stand 
the  light  better  than  any  other  form  of  the  same  chemical 
composition  is  not  at  the  present  time  clear  to  us  and  we 
do  not  think  it  advisable  to  advance  a  theory  in  this 
regard  so  we  will  content  ourselves  with  stating  a  fact 
that  has  come  under  our  observation  and  leave  the 
solution  to  another  time. 


CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 


PROPERTIES  OF  THE  CHROME  YELLOWS 

Normal  Lead  Chromate  and  mixtures  of  Normal  Lead  Chromate  with  Lead 
Sulphate  or  White  Lead  and  Basic  Lead  Chromate 


Name 

Top  Hue 

Under  Hue 

Fineness 

Incompatibility 

Chrome  yellow 
lemon  hue. 

Lemon  yellow. 

Slightly  green. 

(Normal    lead 

There    are     a 

All  of  this  class 

chromate    with 

number  of  differ- 

of yellows  are  dis- 

lead sulphate  or 

ent  top  hues  un- 

tinguished by  a 

white  lead.) 

der     this     class 

more      or      less 

from  a  very  light 

green  under  hue. 

sulphur  color  to  a 

moderately  dark 

lemon. 

Chrome  yellow. 

(Normal  chro- 

Deep    yellow, 

Slightly  red. 

mate  of  lead.) 

slightly  orange. 

Other    modifi- 

There   are     a 

As  these  colors 

Cannot  be 

cations    between 

number  of  hues 

near  chrome  yel- 

mixed with  sul- 

the normal  lead 
sulphate  and  the 
lead  sulpho-chro- 
mates    or    mix- 

between  chrome 
yellow  of  lemon 
hue  and  chrome 
yellow    getting 

low     they     pass 
from     green     to 
yellow  and  then 
to  red  in  under 

Good     soft 
colors. 

phur  colors  or 
used  in  the 
presence  of  al- 
kalies. 

tures  of   normal 

deeper  and  more 

hue. 

lead       chromate 

orange    as    they 

and  white  lead. 

near  the  normal 

lead      chromate. 

The  middle  hue 

of  these  is  called 

chrome      yellow 

medium. 

- 

Mixtures       of 

There    are    a 

There    are    a 

small  amounts  of 

number  of  hues 

number  of  hues 

basic  lead  chro- 

between   chrome 

between    chrome 

mates  with  nor- 

yellow    and 

yellow     and 

mal    lead    chro- 

chrome yellow  of 

chrome   yellow 

mate. 

orange  hue  that 

orange  hue  that 

are  not  quite  or- 

are progressively 

anges  but  which 

more  red  as  the 

are  more  red  than 

amount  of  basic 

chrome  yellow. 

lead  chromate  in- 

creases. 

PROPERTIES  OF  INK-MAKING  MATERIALS 


PROPERTIES  OF  THE  CHROME  YELLOWS  —  Continued 


Name 

Abrasive 
Qualities 

Drying 

Shortness 

Flow 

Oil 

Absorption 

Chrome  yellow 

lemon  hue. 

(Normal  lead 

chromate   with 

lead     sulphate 

or  white  lead.) 

Chrome  yellow 

(Normal    chro- 

mate of  lead.) 

Other   modi- 

Dry well. 

fications       be- 

Not    too 

tween  the  nor- 

fast. 

mal    lead    sul- 
phate and  the 
lead       sulpho- 
chromates      or 

Do  not  ex- 
ert any  abra- 
sive    quali- 
ties. 

Drying  in- 
creases as  the 
composition 
of  the  yellow 

Have  good 
length  in  oil 
or  varnish. 

Have  good 
flow. 

Low    oil 
absorption. 
Work  up 
well  in  ve- 

mixtures of  nor- 

nears the  nor- 

hicles. 

mal  lead  chro- 

mal lead  chro- 

mate and  white 

mate. 

lead. 

Mixtures    of 

small   amounts 

of    basic    lead 

chromates  with 

normal        lead 

chromate. 

52         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 


PROPERTIES  or  THE  CHROME  YELLOWS  —  Continued 


Name 

Smoothness 

Fastness  to 
Light 

Atmos- 
pheric In- 
fluences 

Value  as  an 
Ink-making 
Pigment 

Chrome  yellow. 

Lemon  hue. 

(Normal    lead 

chromate      with 

lead  sulphate  or 

white  lead.) 

Chrome  yellow. 

(Normal  chro- 

- 

•*• 

mate  of  lead.) 

Not  very  fast 

to  light.  Darken 

Other    modifi- 
cations   between 
the  normal  lead 
sulphate  and  the 
lead  sulpho-chro- 
mates    or    mix- 
tures of  normal 
lead       chromate 
and  white  lead. 

Make    smooth 
inks. 

somewhat  on  ex- 
posure.      Those 
colors  made  with 
lead    sulphate 
darken  less  than 
those  without  sul- 
phate. 
Normal     lead 
chromates  do  not 
darken   much   if 

Sulphur 
gases  in  the 
air  affect 
all  chrome 
yellows. 

Very  good  on 
account    of    the 
variety    of    hues 
and   their  work- 
ing qualities. 
They    are    an 
important     class 
of   pigments   for 
all  kinds  of  print- 
ing inks. 

they  are  pure 

products. 

Mixtures  of 

small  amounts  of 

basic  lead  chro- 

mates  with  nor- 

mal   lead    chro- 

mate. 

PROPERTIES  OF  INK-MAKING  MATERIALS  53 

4.     GREENS 

CHROME  GREEN 

While  there  are  a  number  of  different  mineral  greens  on 
the  market  the  only  green  of  any  importance  to  the  ink 
maker  is  the  so-called  chrome  green,  which,  in  reality 
is  a  mechanical  mixture  of  chrome  yellow  and  prussian 
blue.  This  green  can  be  prepared  in  two  ways,  wet  and 
dry,  but  only  that  produced  by  the  wet  process  is  suit- 
able for  printing  inks.  There  are  a  great  many  hues  of 
this  pigment  that  can  be  attained  by  variations  in  the 
process  of  manufacture  and  the  materials  used,  so  many 
in  fact,  that  nothing  but  a  general  description  of  the 
method  of  making  this  pigment  can  be  attempted  here. 

Chrome  green  for  use  in  printing  inks  should  be  made 
only  from  pure  chrome  yellow  and  prussian  blue  without 
the  addition  of  barytes  or  any  other  base  except  lead 
sulphate.  The  chrome  yellow  should  be  precipitated 
first  and  washed  several  times  and  freshly  made  prussian 
blue  run  into  it  in  the  form  of  a  thin  paste,  with  constant 
stirring.  The  prussian  blue  best  suited  for  making 
bright  greens  is  a  blue  of  slight  reddish  hue  about  half 
between  a  blue  of  green  hue  and  a  blue  of  decided  red  hue. 

The  different  hues  of  chrome  green  are  produced  by 
varying  hues  of  chrome  yellow  and  different  amounts  of 
prussian  blue.  Thus,  when  mixed  with  the  proper  amount 
of  blue,  a  chrome  yellow  of  lemon  hue  will  give  a  bright, 
light  chrome  green.  While  a  chrome  yellow  (normal 
lead  chromate)  will  give  a  very  dark  green.  Between 
these  two  almost  any  hue  can  be  produced  by  varying 
the  amount  of  blue  and  using  a  lighter  or  darker  yellow. 
Care  should  be  taken  not  to  employ  a  yellow  of  decided 


54         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

orange  hue  or  a  yellow  with  a  red  under  hue  as  the  resul- 
tant green  will  be  an  olive  or  a  dirty  green.  The  yellows 
for  making  chrome  greens  should  always  be  the  lightest 
and  brightest  that  can  be  made. 

Some  firms  have  been  very  successful  in  making  a 
bright,  resistant  green  by  the  use  of  zinc  yellow,  that  is, 
the  chromate  of  zinc.  It  has  been  our  experience,  how- 
ever, that  this  color  does  not  give  the  working  qualities 
that  the  lead  chromate  greens  give. 

CHROMIUM  OXIDE 

The  oxide  of  chromium  is  really  the  best  and  fastest 
green  that  can  be  secured  but  it  can  only  be  obtained 
at  its  best  in  one  hue.  It  is  also  a  very  expensive  color, 
too  expensive  in  fact  for  general  use  except  as  a  tinting 
color  or  for  the  highest  grades  of  work. 

PROPERTIES  OF  CHROME  GREENS 


Name 

Top  Hue 

Under  Hue 

Fineness 

Incompatibility 

Chrome  green. 

Varies  in  top 

Varies  from  a 

Always  fine. 

Incompatible 

hue  from  a  light 

light  green  to  a 

with     sulphur 

green  to  almost 

very  dark  blue. 

colors    and    al- 

black. 

kalies. 

Chromium 

oxide. 

Medium  green. 

Medium  green. 

Fine. 

Unaffected. 

Name 

Drying 

Shortness 

Flow 

Oil  Absorption 

Chrome  green. 

Dries  well. 

Makes  a  long 

Flows  well. 

Low,       mixes 

ink. 

well     with     ve- 

hicles. 

Chromium 

oxide. 

Dries  well. 

Long  in  oils. 

Flows  well. 

(Same  as  above.) 

PROPERTIES  OF  INK-MAKING  MATERIALS 
PROPERTIES  OF  CHROME  GREENS  —  Continued 


55 


Name 

Fastness  to 
Light 

Atmospheric 
Influence 

Value  as  an  Ink-making 
Pigment 

Chrome 
green. 

Fast  to  light. 

Blues  some- 
what on  expo- 
sure. 

A  very  valuable  pigment  on 
account  of  its  price  and  stability 
under  all  conditions  except  those 
of  an  alkaline  nature. 

Chromium 
oxide. 

Absolutely 
fast  to  light. 

Fast  to  all  at- 
mospheric influ- 
ences. • 

An  excellent  pigment  under  all 
conditions  but  too  expensive  ex- 
cept for  the  highest  kind  of  work. 

5.     ORANGES 

CHROME  YELLOW  ORANGE 

The  chrome  yellow  oranges,  which  include  all  the  hues 
of  orange  between  chrome  yellow  orange  hue  and  chrome 
yellow  red  hue  are  very  important  pigments.  They  are 
the  best  mineral  oranges  for  printing-ink  work.  Chrome 
yellow  orange  hue  is  a  mixture  of  normal  lead  chromate 
and  basic  lead  chromate,  while  chrome  yellow  red  hue  is 
the  basic  chromate  of  lead.  These  hues,  which  have  a 
very  wide  range,  are  produced  by  increasing  the  amount 
of  basic  lead  chromate  in  the  pigment  until  it  finally  con- 
sists entirely  of  the  basic  chromate,  which  is  chrome 
yellow,  red  hue. 

A.  Chrome  Yellow,  Orange  Hue.  — This  is  a  bright 
pigment  of  true  orange  hue.  It  is  generally  made  by  con- 
verting part  of  the  normal  lead  chromate  of  the  chrome 
yellows  into  basic  lead  chromate,  by  treatment  with 
caustic  soda.  If  normal  lead  chromate  is  treated  directly 
with  caustic  soda  there  will  be  a  loss  of  chromium,  which 
goes  off  in  the  filtrate  as  sodium  chromate.  In  the  fol- 


56         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

lowing  method,  which  gives  a  bright,  soft,  pigment  of 
decided  orange  hue  and  good  color  strength,  the  loss  of 
chromate  is  avoided,  as  the  sodium  chromate  formed  in 
the  decomposition  of  the  normal  lead  chromate  is  used 
up  by  the  lead  sulphate.  By  varying  the  amount  of 
sulphate  and  caustic  soda  any  number  of  different 
degrees  of  orange  hue  can  be  obtained. 

Solution  No.  1     100    Ibs.  Lead  Nitrate  in  600  Ibs.  water  ©  50°  F. 

2  18|     "    Sodium  Bichromate  in  600  Ibs.  water  ©  50°  F. 

3  12|     "    Sulphuric  Acid  66°  Be" 

4  Solutions  No.  2  and  No.  3  mixed 

5  2000   "   Water  at  50°  F. 

6  Caustic  Soda  40°  Be 

Run  solutions  No.  i  and  No.  4  simultaneously  into  No. 
5,  decant  off  the  top  liquor,  heat  No.  5  to  boiling  and 
add  No.  6  until  the  desired  color  is  reached. 

B.  Chrome  Yellow,  Red  Hue.  —  This  pigment  is  basic 
chromate  of  lead.  It  has  a  dull  orange  red  top  hue  and 
an  under  hue  of  orange  with  a  slight  red  hue.  It  could 
be  classed  as  a  red  but  on  account  of  its  chemical  com- 
position and  the  decided  orange  of  its  under  hue  it  is 
more  properly  classed  as  an  orange. 

The  following  formula  will  give  a  good  type  of  this 
pigment : 

Solution  No.  1    100  Ibs.   White  Lead,  well  ground  in  30  Ibs.  of  water. 

2  31    "     Potassium  Bichromate  in  110  Ibs.  of  water,  this  solution 

being  neutralized  with  '  281  Ibs.  of  crystallized 
Soda. 

3  No.  2  is  heated  to  boiling  until  the  Carbonic  Acid  is  ex- 

pelled and  No.  1  is  added  as  slowly  as  possible.  The 
resultant  precipitate  is  then  drawn  off  into  another  tub 
and  washed  twice.  Enough  water  is  then  added  to 
make  it  up  to  the  original  volume  of  the  mixed 
solutions. 

4  Sulphuric  Acid  66°  Be.,  about  4  Ibs.  to  every  calculated 

100  Ibs.  of  Basic  Lead  Chromate  in  No.  3. 


PROPERTIES  OF  INK-MAKING  MATERIALS  57 

Run  No.  4  into  No.  3  in  the  cold  with  constant  stir- 
ring. The  material  is  then  washed  once  with  hot 
water  and  dried. 

ORANGE  MINERAL 

Orange  mineral  is  another  pigment  of  orange  hue;  but 
its  value  as  an  ink-making  pigment  is  not  nearly  so  great 
as  that  of  chrome  orange,  since  it  has  several  very  serious 
physical  defects.  Orange  mineral  consists  of  PbO  and 
PbO2  chemically  combined  to  make  Pb3O4,  in  the  follow- 
ing percentages,  35  per  cent  PbO2  and  65  per  cent  PbO. 
This  percentage  varies  a  little  in  different  samples.  Three 
varieties  of  orange  mineral  are  recognized  in  the  color 
trade  namely,  German,  French  and  American.  They  are 
all  of  approximately  the  same  chemical  combination,  but 
differ  greatly  from  each  other  in  physical  characteristics. 
This  is  due  entirely  to  differences  in  the  raw  materials 
used  to  produce  the  pigment. 

The  most  serious  drawback  to  orange  mineral  is  its 
tendency  to  form  a  soap  with  linseed  oil  and  thus  to 
produce  a  livery  ink,  and  the  fact  that  an  ink  made  from 
it  will  harden  so  that  it  is  unfit  for  use  after  standing  for 
a  short  while.  French  orange  mineral  shows  this  defect 
least  of  the  three  varieties,  while  American  orange  min- 
eral is  on  this  account  practically  worthless  for  printing- 
ink  work.  All  of  the  orange  minerals  settle  out  badly  and 
show  a  great  many  defects  in  working  qualities.  The 
different  varieties  also  have  slightly  different  hues. 

Methods  of  Manufacturing  Orange  Minerals.  —  Both 
French  and  German  orange  minerals  are  made  by 
heating  white  lead  in  a  muffie  furnace  until  the  carbonic 
acid  and  moisture  are  driven  off  and  the  resulting  lead 


CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 


oxide  converted  into  the  proper  proportions  of  dioxide 
and  monoxide.  French  orange  mineral  is  made  by  using 
white  lead  made  according  to  the  French  method  while 
German  orange  mineral  is  made  from  white  lead  made 
according  to  the  German  method.  The  American  orange 
mineral,  which  is  nothing  but  what  is  ordinarily  called 
red  lead  of  a  slight  orange  hue,  is  made  by  heating  lith- 
arge in  a  muffle  furnace. 

PROPERTIES  OF  THE  ORANGES 


Name. 

Top  Hue 

Under  Hue 

Fineness 

Fastness  to 
Light 

Incom- 
patibility 

Chrome 

yellow, 

Bright  orange 

Yellow  orange 

Very  Fast. 

orange  hue 

Chrome 
yellow, 

Dull  orange 

rprl 

Orange     of 
decided     yel- 

Very Fast. 

red  hue. 

led. 

low  hue. 

French 

Bright    or- 

Bright   or- 

Darkens 

orange 
mineral. 

ange  of  slight 
red  hue. 

ange  of  slight 
red  hue. 

Impalpable 
powder. 

slightly  under 
light. 

Affected  by 
sulphur  colors 

Bright    or- 

German 

Bright    or- 
ange, slightly 

ange    with    a 
slight  red  hue. 

Dark  ens 

orange 
mineral. 

lighter     than 
the  French. 

More    yellow 
than       the 

slightly  under 
light. 

French. 

American 

Orange    of 

Orange     of 

Darkens 

orange 

decided      red 

decided      red 

slightly  under 

mineral. 

hue. 

hue. 

light. 

PROPERTIES  OF  INK-MAKING  MATERIALS 


59 


PROPERTIES  OF  THE  ORANGES  —  Continued 


Name 

Atmospheric 
Influences 

Abrasive 
Qualities 

Oil 
Absorption 

Drying 

Shortness 

Exert   con- 

Chrome 

siderable  dry- 

yellow, 

ing       action. 

Is  of  good 

orange 

Care     should 

.ength. 

hue. 

3e    taken    in 

using  driers. 

Exert   con- 

Chrome 
yellow, 
red  hue. 

Affected    by 
sulphur  gases. 

Not  abrasive. 

Very  low. 

siderable  dry- 
ing      action. 
Care     should 
be    taken    in 

Is  of  good 
length. 

using  driers. 

French 

orange 

Dries  quickly. 

Fairly  long. 

mineral. 

German 
orange 
mineral. 

Dries   very 
quickly. 

Fairly  short. 

American 
orange 
mineral. 

Dries  very 
quickly. 

Very  short. 

60         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 
PROPERTIES  OF  THE  ORANGES  —  Continued 


Name 

Flow 

Smoothness 

Value  as  an  Ink-making  Pigment 

yellow, 

Good. 

Very  important.      A  fairly  cheap   pig- 
ment that  works  well  in  all  kinds  of  ink. 

orange  hue 

Chrome 
yellow, 

Good. 

Used  in  making  mixed  or  degraded  colors 
where  a  red  top  hue  and  yellow  orange 
under  hue  is  desired.      The  only  pigment  of 

red  line. 

this  character  there  is. 

French 
orange 
mineral. 

Flows 
fairly 
well. 

Very  smooth. 

Is  not  of  very  much  value.      But  it  is  the 
best  of  the  three  kinds  of  orange  mineral 
as  it  does  not   thicken  as  readily  as  the 

other  two. 

German 
orange 

Flows 
fairly 

Thickens  up    and    livers    on    standing. 
Not  of  much  value. 

mineral. 

well. 

American 

Does  not 

orange 

flow     very 

Of  no  value  as  an  ink-making  pigment. 

mineral. 

well. 

6.    RUSSETS 

All  the  inorganic  pigments  that  can  be  classed  as  rus- 
sets owe  their  hue  primarily  to  iron  oxide;  the  different 
names  met  with  are  either  given  to  them  as  trade  names 
or  to  differentiate  between  various  hues.  As  a  rule  these 
iron  oxide  pigments,  whether  natural  earth  pigments  or 
artifically  made  by  precipitation  of  iron  or  calcining  by- 
products, have  practically  no  value  as  typographical  ink 
pigments  and  very  little  value  as  plate  ink  pigments  on 
account  of  their  hardness,  which  causes  abrasion  of  the 
plates  in  plate  printing.  Another  drawback  is  the  diffi- 
culty of  getting  them  in  a  fine  state  of  division,  as  any 
slight  coarseness  makes  them  fill  up  the  forms  in  typo- 
graphic work. 


PROPERTIES  OF  INK-MAKING  MATERIALS  6 1 

All  of  these  colors,  on  account  of  their  low  price,  are 
used  on  cheap  poster  work  but  as  the  same  or  even  better 
effects  can  now  be  produced  for  high  grade  work  by  colors 
with  superior  working  qualities  their  work  is  limited  to 
the  above  field  and  to  work  where  an  alkaline  condition 
is  to  be  met  with,  such  as  wrappers  for  soap  and  labels 
for  lye  cans. 

INDIAN  RED 

Indian  red  is  a  clay  containing  a  high  percentage .  of 
iron  oxide.  The  general  way  of  preparing  it  is  to  levigate 
the  crude  color  to  remove  the  sand  and  other  impurities, 
calcine  it  in  a  furnace  and  regrind  the  calcined  product. 
As  can  easily  be  imagined  the  resulting  pigment  lacks  fine- 
ness of  grain  and  is  generally  contaminated  with  fine  sand. 

VENETIAN  RED 

Venetian  red  is  an  iron  oxide  pigment  made  in  two 
ways,  either  by  precipitating  a  solution  of  ferrous  sul- 
phate with  soda  and  calcining  the  precipitate  or  by  cal- 
cining ferrous  sulphate  in  a  muffle  and  then  recalcining 
the  ferric  oxide  with  salt.  The  hue  varies  with  the 
amount  of  salt  used.  This  pigment  is  a  hard  grained 
material  seldom  of  any  degree  of  fineness  due  to  the  dif- 
ficulty of  grinding  it. 

BURNT  UMBER 

Burnt  umber  is  the  calcined  form  of  a  clay  containing 
iron  oxide  and  manganese,  called  raw  umber.  It  is  some- 
what similar  in  physical  characteristics  to  indian  red  and 
is  treated  in  the  same  way.  It  is  rarely  very  fine,  fre- 
quently contains  grit  and  sand,  and  is  not  of  much  value 
except  for  mixing  a  small  quantity  in  an  ink  to  produce 
a  certain  shade. 


62       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

BURNT  SIENNA 

Burnt  sienna  is  the  calcined  product  of  raw  sienna,  an 
earth  containing  a  large  percentage  of  ferric  hydroxide. 
It  is  similar  in  physical  characteristics  to  the  other  iron 
pigments.  Its  value  is  about  the  same  as  that  of  umber. 

7.    CITRINES 

The  pigments  that  can  be  classed  as  citrines  are  the  raw 
forms  of  sienna,  umber  and  ochre.  They  also,  as  do  the 
russets,  owe  their  hues  to  varying  amounts  of  iron  and 
manganese  oxides.  They  have  little  or  no  value  as  ink- 
making  pigments.  The  method  of  preparing  these  pig- 
ments, which  is  practically  the  same  for  all  three, 
consists  in  levigating,  drying  and  grinding.  Care  should 
be  taken  in  drying  as  these  pigments  change  color  at 
high  temperatures. 


PROPERTIES  or  RUSSETS  AND  CITRINES 


Name 

Top  Hue 

Under  Hue 

Fineness 

Incompatibility 

Abrasive 
Qualities 

Dull 

Indian 
red. 

purple 

Dull  brown 
red. 

red. 

Venetian 

Light 
brown 

Dull  brown 

red. 

red. 

red. 

Coarse. 

Can  be  used  with 
any  color  or  base. 

Very 
abrasive. 

Burnt 

Dark 

Dull  yellow 

umber. 

brown. 

brown. 

Dark 

Burnt 
sienna. 

brown 

Light  red 
brown. 

red. 

PROPERTIES  OF  INK-MAKING  MATERIALS 
PROPERTIES  OF  RUSSETS  AND  CITRINES  —  Continued 


Name 

Drying 

Shortness 

Oil  Absorption 

Flow 

Fastness 
to  Light 

Indian  red. 

Quite  high. 

Venetian  red. 
Burnt  umber. 

Dries  poorly. 

Short. 

Quite  high. 
Very  high. 

Poor. 

Fast. 

Burnt  sienna. 

Very  high. 

Name 

Atmospheric 
Influences 

Smoothness 

Value  as  Ink- 
making  Pigments 

Indian  red. 

Venetian  red. 
Burnt  umber. 

Not  affected. 

Very  grainy. 

Poor. 

Burnt  sienna. 

8.    BLACK  PIGMENTS 

From  the  point  of  view  of  wideness  of  use  and  quan- 
tity used  the  black  pigments  are  without  doubt  the  most 
important  ink  pigments.  With  but  one  exception  they 
are  all  manufactured  products  and  all  but  two  of  them 
owe  their  blackness  to  amorphous  carbon.  The  black 
pigments  are  practically  all  good  ink-making  pigments, 
different  ones  being  adapted  to  different  classes  and  pro- 
cesses of  printing;  while  one  or  two  are  valuable  as 
adjuncts,  that  is  as  materials  to  add  to  certain  inks  to 
improve  their  working  qualities. 

The  black  pigments  may  be  primarily  divided  into  five 
classes  as  follows: 


64         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Bone  Black. 

Vine  Black  or  Vegetable  Black. 
Carbon  or  Gas  Black. 
Lamp  or  Oil  Black. 

Miscellaneous  Blacks  (including  natural  blacks  and  certain  blacks  made 
by  patented  processes,  from  by-products  or  from  mixtures  of  certain  others,  that 
do  not  fall  readily  in  to  the  above  classifications). 

A.  Bone  Black.  —  Bone  blacks  are,  as  the  name 
implies,  made  by  the  calcination  of  bones  in  air-tight 
retorts.  They  consist  essentially  of  carbon  and  an  ash, 
consisting  of  calcium  phosophate  and  calcium  carbonate 
with  a  small  amount  of  calcium  sulphate  and  sulphide, 
these  salts  being  the  mineral  constituents  of  the  bones. 
This  ash  amounts  to  about  eighty-five  per  cent  of  the 
black. 

The  bone  blacks  found  on  the  market  are  of  three  dif- 
ferent varieties:  sugar-house  bone  black,  that  is  bone 
black  that  has  already  been  used  to  refine  sugar;  bone 
black  primarily  made  for  use  as  a  pigment  and  acid 
washed  bone  black.  The  method  of  manufacturing  the 
bone  black  is  the  same  in  all  cases  but  on  account  of  the 
after  treatment,  the  different  varieties  have  different  phys- 
ical properties. 

Method  of  Making  Bone  Black.  —  The  general  process 
of  making  bone  black  is  to  select  the  densest  bones,  boil 
them  to  remove  the  fat,  grind  to  a  coarse  powder  and 
burn  them  in  retorts  from  which  the  air  is  excluded  by 
luting.  In  most  bone-black  factories  the  by-products  of 
the  dry  distillation,  ammonium  carbonate,  bone  oil,  etc., 
are  recovered  in  a  suitable  manner.  When  the  bones  are 
thoroughly  calcined  the  retorts  are  allowed  to  cool  and 
the  product  withdrawn. 


PROPERTIES  OF  INK-MAKING  MATERIALS  65 

For  use  in  refining  sugar  the  material  is  left  in  its  gran- 
ular form.  After  being  used  for  filtering  sugar  until  its 
decolorizing  power  is  entirely  used  up  the  black  is  washed, 
ground  wet,  dried,  bolted  and  finds  its  way  to  the  mar- 
ket as  a  pigment. 

In  preparing  bone  black  for  a  pigment  primarily,  the 
dense  hard  bones  are  ground  very  fine,  sifted  and  then 
burnt,  the  products  of  combustion  in  most  cases  being 
burnt  instead  of  recovered.  This,  it  is  claimed,  makes  a 
better  product  than  when  the  by-products  are  recovered, 
although  it  is  impossible  to  see  any  reason  why  this 
should  be  so.  As  in  many  similar  cases  this  appears  to 
be  a  tradition  with  no  practical  foundation.  The  bone 
black  prepared  in  this  way  has  greater  strength  of  color 
and  better  working  qualities  than  sugar-house  bone 
black. 

When  bone  black  is  treated  with  acid  the  calcium  salts 
are  dissolved  out  and  the  result  is  a  very  finely  grained 
carbon  containing  little  or  no  ash,  depending  on  the 
amount  of  acid  treatment.  Acid  treated  bone  black 
has  a  very  deep  black  color  and  in  consequence  of  its 
fine  state  of  division  a  great  deal  of  color  strength.  It  is 
used  as  a  toner  for  slightly  off -colored  or  weak  bone  blacks 
and  as  a  forcing  black  to  bring  up  the  color  on  certain 
classes  of  plate  work.  As  a  toner  for  bone  blacks  it 
is  far  superior  to  lamp  or  carbon  black  on  account  of  its 
lower  oil  absorption  and  its  better  working  qualities. 

The  use  of  bone  black  is  entirely  restricted  to  plate 
printing  inks.  Bone  black  is  also  designated  by  the  plate 
printing  trade  as  hard  black.  It  is  sometimes  put  on  the 
market  in  lumps  or  in  the  form  of  drops,  the  idea  being 
that  blacks  in  this  form  are  purer  and  better  than  the 


66         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

powdered  blacks;  this  is  of  course,  a  great  fallacy  as  the 
pigments  in  both  cases  are  identical. 

B.  Vegetable  or  Vine  Black.  —  Under  the  head  of 
vegetable  or  vine  blacks  are  classed  the  black  pigments 
produced  by  the  dry  distillation  and  carbonization  of 
willow  wood,  wine  yeast,  grape  husks,  grape-vine  twigs, 
spent  tan  bark,  shells,  fruit  pits,  sawdust  or  in  fact  any 
material  of  vegetable  origin. 

The  blacks  made  from  grape-vine  twigs,  grape  husks 
and  wine  yeast  are  the  best  of  this  class  and  the  name 
vine  black  is  derived  from  the  fact  that  they  were  for- 
merly used  exclusively  to  produce  it.  Of  late  years  how- 
ever this  name  has  been  extended  to  take  in  every  variety 
of  black  of  vegetable  origin.  These  vegetable  blacks, 
when  properly  made,  are  of  a  deep  black  color  and  show 
great  strength.  They  consist  of  about  75  per  cent  of 
carbon  and  25  per  cent  of  ash.  The  ash  contains  silica, 
calcium  phosphate,  carbonate  and  sulphate  and  a  small 
amount  of  potassium  carbonate. 

The  vegetable  blacks  can  be  graded  in  the  following 
manner: 

True  vine  black,  that  is  black  from  wine  yeast  or 
grape-vine  twigs. 

Blacks  from  grape  husks. 

Blacks  from  willow  charcoal. 

Blacks  from  spent  tan  bark. 

Blacks  from  fruit  pits. 

The  differences  in  quality  are  due  entirely  to  the  dif- 
ferent physical  properties  exhibited  by  the  products  from 
different  sources:  such  as  differences  in  density,  grain  and 
state  of  division  and  to  the  process  employed  in  carboniz- 
ing them  and  treatment  after  carbonization. 


PROPERTIES  OF  INK-MAKING  MATERIALS  67 

Method  of  Making  Vine  Black.  —  In  the  manufacture 
of  vine  black  practically  the  same  process  is  used  as  in 
the  manufacture  of  bone  blacks,  that  is  the  raw  materials 
are  carbonized  in  the  absence  of  air.  This  is  done  in  a 
suitable  retort,  a  number  of  different  forms  of  apparatus 
being  used,  with  or  without  the  recovery  of  by-products. 

After  the  material  is  burnt,  it  is  well  washed  with  water 
to  remove  the  soluble  alkaline  salts  and  ground.  The 
very  finest  grades  of  vine  black  are  also  acid  washed, 
which  produces  about  the  same  effect  as  it  does  in  the 
case  of  bone  blacks.  In  the  plate  printing  trade  in  which 
trade  they  are  only  used,  they  are  called  soft  blacks. 
Their  principal  use  is  to  give  a  certain  grain  to  bone 
blacks  and  to  give  increased  color. 

C.  Carbon  or  Gas  Black.  —  Carbon  or  gas  blacks  are 
almost  pure  carbon  containing  practically  no  ash.  They 
consist  of  about  92  to  95  per  cent  of  carbon,  the  remainder 
being  moisture  and  unburnt  hydrocarbons  from  the  raw 
material.  The  amounts  of  moisture  and  unburnt  hydro- 
carbons are  of  course  variable  with  the  process  of  manu- 
facture and  the  care  taken  in  collecting  the  finished 
product. 

The  carbon  blacks  are  very  fine  pigments  of  low  spe- 
cific gravity  and  are  consequently  very  bulky.  They  are 
a  very  deep  black  and  make  excellent  typographical  inks 
of  fine  working  qualities.  They  cannot,  however,  be 
used  in  plate  inks  on  account  of  their  high  oil  absorption 
and  lack  of  body  which  makes  them  hard  to  wipe  or 
polish. 

There  is  a  wide  range  in  the  behavior  of  different  car- 
bon blacks  when  made  into  inks,  a  wider  range  than 
there  is  any  apparent  cause  for.  In  working  qualities, 


68         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

the  different  brands  and  grades  of  carbon  black  on  the 
market  exhibit  this  to  a  great  extent.  They  vary  from 
making  short,  tacky  inks  to  making  inks  of  great  natural 
length  and  decided  flow  while  some  carbon  blacks  which 
we  have  had  experience  with,  were  absolutely  worthless 
for  making  any  kind  of  ink,  even  news  ink.  A  great 
difference  will  also  be  found  in  the  behavior  of  different 
carbon  blacks  towards  driers.  The  authors  have  done 
a  great  deal  of  work  along  these  lines  but  have  been 
unable  to  find  any  reason  as  to  why  the  working  qualities 
and  behavior  of  blacks  of  the  same  general  origin  and 
composition  should  vary  in  their  physical  properties  to 
such  an  extent.  By  the  proper  combination  of  varnishes 
and  grades  of  black  almost  any  desired  effect  can  be  pro- 
duced in  typographical  printing  ink  by  the  use  of  this 
pigment. 

Manufacture  of  Carbon  Black.  —  There  are  numerous 
different  methods  of  making  gas  black  which  are  all  sim- 
ilar in  the  essentials.  That  of  burning  natural  or  some 
form  of  producer  gas  with  a  small  supply  of  air  and  col- 
lecting the  soot  in  a  suitable  way  is  the  most  common. 
The  methods  of  burning  the  gas  and  of  collecting  the 
resultant  pigment  vary  greatly,  a  number  of  patents  hav- 
ing been  granted  both  in  this  country  and  abroad  on 
special  apparatus  for  burning  and  collecting  carbon  black. 

The  apparatus  most  commonly  in  use  in  this  country 
at  the  present  day  consists  of  a  burner,  generally  ordinary 
pipe,  but  in  some  cases  a  regular  burner  of  the  Argand 
type,  and  a  water-cooled  surface  for  collecting  the  soot. 
This  water-cooled  surface  is  rotated  above  the  burner 
and  is  provided  with  a  means  for  removing  the  soot  as  it 
accumulates.  The  carbon  black  made  in  this  way  is  a 


PROPERTIES  OF  INK-MAKING  MATERIALS  69 

soft,  bulky,  deep  black  product  and  contains  only  a  small 
amount  of  unburnt  hydrocarbons. 

D.  Lampblack.  —  Lampblacks  like  carbon  blacks  are 
almost  pure  carbon  and  are  similar  in  appearance  to  car- 
bon blacks  with  the  exception  that,  as  a  rule,  they  are  not 
in  such  a  fine  state  of  division  and  contain  more  prod- 
ucts of  distillation.  A  very  fine  calcined  lampblack,  that 
is  one  which  has  been  reheated  after  making,  shows  about 
the  same  properties  as  carbon  black.  As  is  the  case  in 
carbon  blacks,  there  are  a  great  many  grades  of  lamp- 
black on  the  market,  depending  on  the  raw  materials 
used,  the  methods  of  manufacture  and  on  the  state  of 
division  of  the  product.  Each  of  these  grades  shows 
certain  different  physical  properties. 

A  number  of  raw  materials  have  been  and  still  are  used 
for  making  lampblack,  among  which,  may  be  noted, 
naphthalene,  anthracene,  oil  residues,  pitch,  resin  and 
gas  tar  oils,  the  latter  being  the  most  widely  used  at 
present.  Nearly  all  of  the  lampblack  now  on  the  market 
is  made  from  the  "dead  oil"  of  the  gas  house. 

There  are  a  number  of  patents  relating  to  apparatus 
for  burning  and  collecting  lampblack,  the  process  being 
fundamentally  the  same  as  that  used  in  making  carbon 
black.  There  is,  however,  a  difference  in  manipulation 
and  in  the  details  of  the  processes. 

The  most  used  method  of  producing  lampblack  is  as 
follows :  the  material  to  be  burnt  is  introduced  into  a 
cast-iron  furnace,  fitted  with  a  door  for  the  purpose  and 
containing  a  pan  or  receptacle  which  has  been  heated  to 
redness.  This  ignites  the  material  to  be  burnt  and  the 
products  of  combustion  are  led  into  collecting  chambers. 
The  furnace  is  recharged  from  time  to  time  by  ladles, 


70         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

care  being  taken  not  to  allow  too  much  air  to  enter  the 
furnace  during  the  charging.  The  heating  pans  must  be 
changed  and  cleaned  every  few  days. 

The  collecting  chambers  consist  of  flues  with  staggered 
walls  dividing  them  into  compartments.  These  walls 
act  in  a  way  as  baffle  plates  to  stop  the  passage  of  the 
soot  particles.  The  heavier  particles  will  be  deposited 
in  the  first  compartment,  while  the  finer  ones  are  carried 
through  and  are  deposited  at  the  very  end  of  the  collect- 
ing chambers.  The  lampblack  deposited  in  the  first 
compartment  is  large  grained  and  contains  quite  a  large 
percentage  of  unburnt  hydrocarbons  while  that  collected 
in  the  last  compartments  is  in  a  very  fine  state  of  division 
and  is  almost  pure  carbon.  In  some  cases  the  lampblack 
collected  in  these  chambers  is  recalcined  in  steel  drums 
to  rid  it  of  unburnt  hydrocarbons  and  the  resultant  prod- 
uct is  of  almost  as  fine  a  grade  as  carbon  black.  Of 
late  years  carbon  black  has  almost  entirely  taken  the 
place  of  lampblack  in  printing  ink. 

£.    Miscellaneous  Blacks 

A.  Mineral    Black.  —  This   pigment   is   a   clay  shale 
containing  about  thirty  per  cent  of  carbon.     When  prop- 
erly prepared,  that  is  washed  and  ground,  it  forms  a  fine, 
soft   powder.     It   is   sometimes   used   in   making   mixed 
blacks  for  plate  printing  inks. 

B.  Manganese  Black.  —  The  precipitated  dioxide  of 
manganese  makes  a  brownish  black  that  is  of  value  when 
mixed  with  bone  and  vine  blacks  in  the  preparation  of 
plate  printing  ink.     The  admixture  of  a  small  amount  of 
this  material  makes  a  plate  printing  ink  made  from  bone 
and  vine  black  and  prussian  blue  or  from  a  mixed  black 


PROPERTIES  OF  INK-MAKING  MATERIALS  71 

and  prussian  blue  work  better,  and  reduces  the  amount 
of  gathering. 

C.  Magnetic  Pigment.  —  Under    the    name    of  mag- 
netic pigment  a  very  finely  divided  black  oxide  of  iron, 
produced    by   a   patented   process,  is   put   on   the   mar- 
ket.    It  is   useful   in   black  plate  inks   to   give   greater 
density,  smoothness,  and  better  working  qualities.     This 
material  also  has  a  tendency  to  prevent  gathering. 

D.  Special  Blacks.  —  Blacks  for  various  special  pur- 
poses, particularly  for  adding  to  other  materials,  are  made 
from   coke,   lignite   and   certain  by-products.      The   ash 
and  carbon  contents  vary  of  course  with  the  raw  material. 

E.  Mixed  Blacks.    These  are  a  class  of  blacks  made 
up  from  bone  blacks   of  different  kinds,  vine  blacks  and 
combinations  of  the  different  miscellaneous  blacks  men- 
tioned  above  with  the  view  of   overcoming   the   defects 
of   straight   mixtures   of   bone   and   vine   blacks.     They 
contain  between  30  and  50  per  cent  of  ash,  not  over  5 
per  cent  of  which  should  be  insoluble  in  hydrochloric 
acid,  the  remainder  being  carbon.     These  mixed  blacks 
should  never  contain  carbon  black  or  lampblack  as  these 
materials  are  too  hard  to  wipe  and  have  too  high  an  oil 
absorption  for  use  in  plate  inks  for  which  mixed  blacks 
are  only  used. 


72         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 


PROPERTIES  OF  BLACKS 


Name 

Top  Hue 

Under  Hue 

Oil  Absorption 

Fineness 

Bone  black. 

Greenish  black. 

Brownish 
black. 

Fairly  low. 

Should  be  fairly 
fine,  that  is,  they 
should  still  have 

Vine  black. 

Greenish  black 
darker  than  bone 
black. 

Brownish 
black. 

Fairly  low. 

some  grain. 

Carbon  black. 

Deep  black. 

Brownish 
black. 

High. 

Lampblack. 

Deep  black. 

Brownish 
black. 

High. 

Mineral  black. 

Brownish  black. 

Decided 
brown. 

Fairly  low. 

Should  be  im- 
palpable powders. 

Magnetic 
pigment. 

Brownish 
black. 

Decided 
brown. 

Low. 

Manganese 
black. 

Brownish 
black. 

Decided 
brown. 

Low. 

Name 

Flow 

Shortness 

Fastness  to 
Light 

Atmospheric 
Influences 

Bone  black. 

Flows  fairly  well. 

Fairly  short. 

Vine  black. 

Flows  fairly  well. 

Fairly  long. 

Carbon  black. 

Poor. 

Short. 

Lampblack. 
Mineral  black. 

Poor. 
Good. 

Short. 
Fairly  long. 

No  effect. 

No  effect. 

Magnetic 
pigment. 

Good. 

Long. 

Manganese 
black. 

Good. 

Long. 

PROPERTIES  OF  INK-MAKING  MATERIALS 
PROPERTIES  OF  BLACKS — Continued 


73 


Name 

Drying 

Smoothness 

Abrasive 
Qualities 

Incompati- 
bility 

Bone  black. 

Does  not  make  a 
smooth  ink. 

Quite  abrasive. 

Vine  black. 

Does  not  make  a 
smooth  ink. 

Quite  abrasive. 

Carbon  black. 

Lampblack. 
Mineral  black. 

Exert  no 
drying  ac- 
tion. 

Works     up     very 
smooth. 

Works  up  smooth. 

Does  not  make  a 
smooth  ink. 

Not  abrasive. 

Not  abrasive. 
Quite  abrasive. 

Mixes  with 
everything. 

Magnetic 
pigment. 

Works     up     very 
smooth. 

Not  abrasive. 

Manganese 
black. 

Works     up     very 
smooth. 

Not  abrasive. 

Name 


Value  as  an  Ink-making  Pigment 


Bone  black. 

Vine  black. 

Carbon  black. 

Lampblack. 

Mineral  black. 
Magnetic  pigment. 
Manganese  black. 


Of  great  value  as  a  plate  printing  ink  material  although  it 
must  be  mixed  with  vine  black  for  color  and  to  give  the 
proper  working  qualities. 

Of  great  value  as  a  toner  to  mix  with  bone  black  to  give 
color  and  working  qualities  to  black  plate  printing  inks. 

The  most  important  typographical  black,  in  fact  it  is  the 
base  of  all  black  typographical  inks  at  the  present  day. 

Not  much  used  at  present  as  its  place  has  been  taken  by  the 
cheaper  but  similar  carbon  black. 

Used  principal] y  to  mix  with  other  blacks. 
Used  principally  to  mix  with  other  blacks. 
Used  principally  to  mix  with  other  blacks. 


74         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

The  mixed  blacks,  being  mixtures  of  various  amounts 
of  the  above  pigments,  will  have  properties  that  vary 
according  to  properties  and  amounts  of  the  different 
ingredients  used  in  their  manufacture. 

9.    DILUTENTS 

Under  the  head  of  dilutents  are  classed  those  pigments 
that  can  be  used  to  produce  tints  of  the  other  pigments. 
They  are  of  necessity  white  pigments  of  great  covering 
power  and  strength.  The  principle  dilutents  used  in 
printing  ink  manufacture  are,  zinc  white,  white  lead  and 
lithopone.  Of  these  dilutents  the  most  satisfactory, 
working  qualities  and  brightness  of  the  tint  considered, 
is  zinc  white;  lithopone  comes  next,  but  white  lead  is  a 
very  unsatisfactory  tinting  pigment.  These  white  pig- 
ments are  also  used  to  make  printing  inks  for  special 
purposes,  particularly  for  use  on  tin  where  a  white  back- 
ground is  necessary  for  color  printing. 

ZINC  WHITE 

Zinc  white  is  zinc  oxide  of  the  formula  ZnO.  It  is  a 
very  soft  pigment  of  a  good  body  and  covering  power. 
The  process  of  manufacture  consists  in  roasting  either 
metallic  zinc  or  zinc  ore  till  fumes  are  given  off,  burning 
these  fumes  in  an  atmosphere  of  super-heated  air  and 
carbon  monoxide  which  accelerates  the  oxidation  of  the 
zinc  and  condensing  the  resulting  oxide  in  suitable  cham- 
bers. As  is  the  case  in  the  preparation  of  lampblack, 
the  zinc  oxide  deposited  first  is  coarse  and  heavy  and 
frequently  contains  particles  of  metallic  zinc,  while  that 
deposited  farthest  away  from  the  retort  or  rotary  fur- 


PROPERTIES  OF  INK-MAKING  MATERIALS  75 

nace  is  the  lightest  and  finest  grade.  The  different  raw 
materials  and  the  care  with  which  the  process  is  carried 
out  produce  the  different  grades  of  zinc  oxide. 

Zinc  oxide  can  be  mixed  with  any  other  pigment  and 
is  not  influenced  either  by  light  or  atmospheric  conditions. 

LITHOPONE 

Lithopone  is  a  mixture  of  artificial  barium  sulphate  and 
zinc  sulphide.  It  is  a  soft  white  pigment  of  good  cover- 
ing power,  in  fact,  its  covering  power  is  very  little  inferior 
to  white  lead  and  it  can  be  used  with  excellent  results 
to  form  tints,  although  not  quite  as  valuable  in  this 
respect  as  zinc  white,  which  has  superior  working  qualities. 

Method  of  Making  Lithopone.  —  The  following  is  the 
general  method  of  manufacturing  lithopone.  Natural 
barytes  is  thoroughly  mixed  with  finely  ground  lignite 
in  the  proportion  of  about  100  pounds  barytes  to  38 
pounds  lignite.  This  mixing  is  best  done  by  grinding  the 
two  materials  together  in  the  wet  way,  as  the  yield  of 
barium  sulphide  depends  to  a  great  extent  on  the  inti- 
macy of  this  mixture.  The  mixture  is  then  dried  and 
put  into  fireclay  retorts  with  air-tight  covers,  the  retorts 
themselves  being  provided  with  suitable  outlets  for  the 
products  of  combustion.  These  retorts,  which  are  gen- 
erally arranged  in  batteries,  are  heated  from  the  outside. 
The  reduction  of  barium  sulphate  takes  about  four  hours 
and  the  material  in  the  retorts  should  be  turned  after 
about  half  this  time.  The  turning  should  be  done  rapidly 
to  prevent  reoxidation  of  the  barium  sulphide  which 
takes  place  very  readily  at  high  temperatures.  When 
the  reduction  is  complete  the  barium  sulphide  is  dumped 
into  air-tight  iron  boxes  to  cool.  Care  should  be  taken 


76         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS' 

to  have  as  pure  barytes  as  possible,  as  impurities  will 
have  an  injurious  effect  on  the  resulting  lithopone. 

The  barium  sulphide  is  then  dissolved  in  water  and  a 
solution  of  zinc  sulphate  free  from  iron  is  made.  These 
two  solutions,  the  strength  of  each  being  known,  are  run 
into  each  other  in  approximately  molecular  proportions. 
There  should,  however,  be  an  excess  of  zinc  sulphate. 
The  precipitate  is  washed  and  dried,  calcined  in  retorts 
until  cherry  red  and  quenched  suddenly  in  cold  water, 
after  which  it  is  ground  in  wet  mills  for  a  long  time, 
pressed,  dried  and  reground  dry. 

Lithopone  varies  in  the  amount  of  zinc  sulphide,  the 
larger  the  amount  the  better  will  be  the  product.  Brands 
of  lithopone  on  the  market  show  a  variation  in  the 
amount  of  zinc  sulphide  from  15  to  33  per  cent. 

WHITE  LEAD 

White  lead  is  a  mixture  of  basic  lead  carbonate  and 
lead  hydrate  with  the  formula  2  PbCO3PbH2O2.  As  white 
lead  is  of  little  value  as  an  ink-making  pigment  and  the 
general  methods  of  its  production  are  well  known,  a 
brief  explanation  of  the  differences  between  the  French 
and  German  methods  of  preparation  is  all  that  will  be 
given  here.  The  German  process  depends  on  the  corro- 
sion of  metallic  lead  by  acetic  acid,  the  action  being 
accelerated  by  heat,  and  the  conversion  of  the  basic  lead 
acetate  into  lead  carbonate  by  the  introduction  of  car- 
bonic acid  gas  into  the  acetic  acid  vapors.  The  French 
process  consists  in  treating  a  solution  of  basic  lead  acetate 
with  carbon  dioxide. 

French  and  German  white  leads  show  different  char- 
acteristics; that  made  by  the  German  process,  showing 


PROPERTIES  OF  INK-MAKING  MATERIALS 


77 


more  covering  power  but  being  inferior  in  whiteness  and 
brillancy  to  the  French.  German  white  lead  also  has 
less  oil  absorption.  These  differences  are  partly  due  to 
physical  structure  and  partially  to  varying  proportions 
of  lead  hydroxide  and  carbonate. 

PROPERTIES  OF  DILUTENTS 


Name 

Fineness 

Covering  Power 

Strength 

Incompatibility 

White 
lead. 

Very  great. 

Great. 

Cannot  be  used 
with  sulphur  colors. 

Litho- 
pone. 

Impalpable 
powder. 

Fair. 

Fair. 

Cannot  be  used 
with  lead  colors. 

Zinc 
white. 

Good. 

Good. 

Can  be  used  with 
any  color. 

Name 

Fastness  to 
Light 

Atmospheric 
Influences 

Oil 
Absorption 

Flow 

White 
lead. 

Yellows  on  ex- 
posure to  light. 

Blackens  in  air 
due    to    sulphur 
gases. 

Low. 

Good. 

Litho- 
pone. 

Darkens  on  ex- 
posure to  light. 

Affected  some- 
what. 

Fairly  low. 

Good. 

Zinc 
white. 

Does  not  change. 

Not  affected. 

Low. 

Fairly  good. 

78          CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 


PROPERTIES  OF  DILUTENTS  —  Continued 


Name 

Shortness 

Smoothness 

Abrasive 
Qualities 

Value  as  a  Dilutent 

White 

Fairly  long. 

Makes     a 

Not  of  much  value. 

lead. 

smooth  ink. 

Chalks  through  when 

used  as  a  dilutent. 

Litho- 

Fairly  long. 

Makes     a 

Can    be    used    in 

pone. 

smooth  ink. 

both  plate  and  typo- 

graphic   ink.      Mix- 

tures   of    aluminum 

Not  abrasive. 

hydrate     and     zinc 

white  give  better  re- 

sults in  typographic 

work. 

Zinc 

Quite  long. 

Very  smooth. 

Of  exceptional  val- 

white. 

ue  for  making  tints 

and   on   account   of 

its  working  qualities 

in   both    plate    and 

typographic  inks. 

The   best   of    the 

white  pigments. 

10.     BASES 

In  the  manufacture  of  printing  inks  there  is  a  class  of 
pigments  that  are  of  no  value  as  pigments  when  used  by 
themselves,  but  form  a  very  important  group  when  used 
with  other  pigments.  These  pigments  are  what  are 
known  as  bases.  That  is,  they  are  used  to  give  body  to 
and  to  carry  other  pigments.  The  bases  have  very  little 
or  no  coloring  power  of  their  own  but  impart  to  the  pig- 
ments they  are  used  with,  working  qualities  and  body. 
They  are  in  a  few  instances  also  used  to  produce  tints. 


PROPERTIES  OF  INK-MAKING  MATERIALS  79 

The  bases  are  used  for  a  number  of  different  purposes 
and  to  produce  a  number  of  different  results  as  is  shown 
by  the  following  examples:  for  instance,  in  cases  where  a 
pigment  shows  a  high  oil  absorption  the  mixture  of  a 
base  of  low  oil  absorption  will  often  overcome  this  defect. 
A  certain  amount  of  base  added  to  a  pigment  which  in 
itself  is  quick  drying  will  sometimes  make  an  ink  of 
moderate  drying  qualities.  In  plate  printing  work  the 
defect  of  striking  through,  gathering,  softness  and  sticki- 
ness can  often  be  overcome  by  the  use  of  a  proper  base. 
The  bases  are  also  extensively  used  as  carriers  for  the 
organic  dyes  in  the  manufacture  of  lakes. 

The  principal  bases  are  barytes  (natural  barium  sul- 
phate) blanc  fixe  (artifical  barium  sulphate),  paris  white 
(calcium  carbonate),  aluminum  hydrate,  magnesium  car- 
bonate and  calcium  sulphate.  Of  these  aluminum  hy- 
drate, blanc  fixe  and  magnesium  carbonate  are  the  only 
ones  which  are  of  value  in  typographical  inks. 

BARYTES 

The  natural  sulphate  of  barium  is  found  more  or  less 
purely  in  almost  all  parts  of  the  world.  It  is  mined, 
separated  into  classes  according  to  its  whiteness  and 
ground.  Barytes  requires  a  great  deal  of  grinding  to 
reduce  it  to  the  proper  fineness  and  the  best  varieties 
are  water  floated  after  grinding.  In  a  great  many  in- 
stances a  small  amount  of  ultramarine  blue  is  added  to 
the  product  to  heighten  its  whiteness.  This  is  frequently 
done  when  the  material  is  contaminated  with  iron,  the 
blue  destroying  the  red  or  yellow  hue  imparted  by  the  iron. 

Barytes  is  a  heavy  white  mineral  of  a  specific  gravity 
between  3.9  and  4.5.  It  is  absolutely  indifferent  to  all 


8o         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

other  chemicals,  even  acids,  and  can  only  be  decomposed 
by  fusion  with  alkalies.  It  has  very  little  covering 
power  and  can,  therefore,  be  added  to  other  pigments 
without  affecting  their  strength,  and,  having  a  low  oil 
absorption,  it  is  of  great  value  when  mixed  with  pig- 
ments which  absorb  a  great  deal  of  oil  or  varnish.  On 
account  of  its  density  and  grain,  barytes,  when  mixed 
with  pigments  for  plate  inks,  overcomes  a  great  many 
of  the  defects  in  working  qualities  inherent  in  many 
mineral  pigments;  particularly  is  this  true  of  the  chrome 
colors  which  are  of  little  value  as  plate  inks  by  themselves. 
For  fine  work  the  barytes  should  always  be  added  in 
the  manufacture  of  the  ink  itself  and  not  as  an  adulter- 
ant in  the  dry  color.  Water  floated  barytes  is  superior 
for  plate  inks  to  blanc  fixe  because  of  its  grain  which 
makes  the  ink  wipe  clean  and  polish  well.  Very  finely 
ground  barytes  is  also  of  great  value  as  a  base  for  organic 
lakes.  The  character  of  the  dye  and  the  method  of  pre- 
cipitation exert  a  great  influence  on  the  value  of  barytes 
as  a  lake  carrier. 

PARIS  WHITE 

Paris  white  is  practically  pure  calcium  carbonate.  It 
is  prepared  by  levigating  chalk  with  water  to  remove 
grit  and  other  physical  impurities.  Chalk,  being  an 
amorphous  form  of  calcium  carbonate,  makes  a  far 
better  base  than  ground  limestone. 

Paris  white  is  a  soft  pigment  with  a  specific  gravity  of 
about  2.5.  It  has  very  little  covering  power  and  dries 
quite  slowly.  It  is  generally  mixed  with  barytes  in  plate 
inks  to  improve  the  polishing  and  is  used  to  some  extent 
in  making  organic  lakes. 


PROPERTIES  OF  INK-MAKING  MATERIALS  8 1 

ALUMINUM  HYDRATE 

Aluminum  hydrate  is  a  very  important  base  both  for 
printing  inks  and  organic  lakes.  When  added  to  plate 
inks  it  makes  them  work  better,  particularly  in  the 
polishing.  In  typographic  inks  it  increases  the  length 
and  flow,  correcting  any  tendency  to  shortness  and  unequal 
distribution.  It  is  also  used  with  good  effect  in  inks  that 
dry  too  much  themselves,  acting  in  these  cases  like  a 
reducer.  Inks  that  do  not  grind  up  smooth  are  also 
helped  by  the  addition  of  aluminum  hydrate. 

Aluminum  hydrate  has  the  formula  A12(OH)6,  but  most 
of  the  commercial  aluminum  hydrate  consists  of  a  mix- 
ture of  basic  aluminum  sulphate  and  aluminum  hydrate. 
This  condition  arises  from  the  fact  that  basic  aluminum 
sulphate  is  not  very  readily  converted  by  sodium  car- 
bonate into  aluminum  hydrate  in  cold  solutions  and  it  is 
necessary  to  precipitate  the  hydrate  in  cold  solutions  in 
order  to  get  a  soft  and  powdery  product  on  drying. 
Aluminum  hydrate  precipitated  by  alkaline  carbonates 
in  hot  solutions  dries  hard  and  horny.  Therefore,  when 
precipitation  takes  place  in  the  cold  a  part  of  the  basic 
aluminum  sulphate  formed  in  the  process  is  left  uncon- 
verted. 

The  method  of  manufacturing  aluminum  sulphate  is 
as  follows: 

The  solution  of  aluminum  sulphate  is  treated  with  an 
excess  of  sodium  carbonate  with  rapid  stirring  until  the 
carbonic  acid  ceases  to  be  evolved.  It  is  then  washed 
and  dried.  This  process  as  stated  above  gives  a  su- 
perior product  when  dried  than  when  the  solution  is 
boiled. 


82      CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

BLANC  FIXE 

Blanc  fixe,  which  is  the  artificial  sulphate  of  barium,  is 
prepared  from  barytes  by  calcining  finely  ground  barytes 
with  powdered  coal  and  dissolving  the  resultant  barium 
sulphide  in  hydrochloric  acid  by  which  process  barium 
chloride  is  obtained.  The  amount  of  barium  chloride 
in  the  solution  is  determined  by  its  gravity.  It  is  pre- 
cipitated by  a  weak  solution  of  sulphuric  acid  or  sodium 
or  magnesium  sulphate  in  the  exact  quantity  to  use  up 
all  the  barium  chloride.  When  sulphuric  acid  is  used, 
the  solution  must  be  mixed  cold,  but  when  sulphates  are 
used  it  is  best  to  conduct  the  operation  hot  as  a  better 
filtering  product  is  obtained  under  these  conditions. 

Blanc  fixe  is  in  a  great  deal  finer  state  of  division  than 
the  natural  sulphate  and  lacks  its  grain,  a  quality  which 
is  of  great  value  in  plate  inks.  When  used  as  a  base  for 
organic  pigments  blanc  fixe  is  generally  precipitated  sim- 
ultaneously with  the  coloring  matter,  using  a  solution  of 
barium  chloride  and  a  soluble  sulphate. 


PROPERTIES  OF  INK-MAKING  MATERIALS 


PROPERTIES  OF  BASES 


Name 

Fineness 

Covering 
Power 

Incompatibility 

Fastness 
to  Light 

Oil  Ab- 
sorption 

Natural 

When  water 

Fair. 

Mixes    well    with 

Low. 

barytes. 

floated    it    is 

everything. 

fairly  fine. 

Paris 

Somewhat 

Practically 

With   colors   that 

Fairly  low 

white. 

coarse. 

none. 

have  a  trace  of  acid 

paris      white      will 

cause   swelling,   e.g. 

Prussian  blues. 

Fast. 

Blanc  fixe. 

Impalpable 

Fair. 

Mixes  with  every- 

Fairly 

^ 

powder. 

thing. 

high. 

Aluminum 

Impalpable. 

Practically 

Mixes    well    with 

Very  high. 

hydrate. 

transparent. 

everything. 

Magnesium 

Impalpable. 

Practically 

Mixes    well    with 

Very  high. 

carbonate. 

none. 

everything. 

Name 

Atmospheric 
Influences 

Shortness 

Flow 

Smoothness 

Abrasive 
Qualities 

Natural 
barytes. 

Fairly  long. 

Fair. 

Grainy. 

Somewhat 
abrasive. 

Paris  white. 

Is  short. 

None. 

Fairly  smooth. 

Slightly 
abrasive. 

Blanc  fixe. 

Is    not    af- 
fected. 

Fairly  short. 

Good. 

Very  smooth. 

Not 
abrasive. 

Aluminum 
hydrate. 

Very  long. 

Fairly 
good. 

Very  smooth. 

Not 
abrasive. 

Magnesium 
carbonate. 

Fairly  long. 

None. 

Very  smooth. 

Not 
abrasive. 

CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 


PROPERTIES  OF  BASES  —  Continued 


Name 


Softness 


Value  as  a  Base  in  Ink  and  Color  Making 


Natural  barytes 
Paris  white. 
Blanc  fixe. 

Aluminum 
hydrate. 


Magnesium 
carbonate. 


Not  very  soft. 

Not  very  soft. 

Very  soft. 

Sometimes 
very  soft  and 
sometimes  hard 
and  horny. 

Only  the  soft 
hydrate  should 
be  used. 

Very  soft. 


Very  valuable  as  a  base  for  plate  inks. 
Valuable  principally  as  a  base  for  plate  inks. 

Valuable  as  a  base  in  typographic  inks  and 
as  a  carrier  for  lakes. 

Exceptionally  valuable  as  a  base  for  typo- 
graphic inks  and  for  a  carrier  in  organic  lakes. 
It  is  also  useful  in  plate  printing  inks. 


Is  used  principally  as  a  base  in  lithographic 
and  offset  inks. 


11.     ORGANIC  LAKES 

The  organic  lakes  consist  of  a  dye  and  a  base  or  carrier. 
There  are  three  general  ways  of  making  these  lakes,  all 
other  methods,  except  in  some  special  cases,  being  modifi- 
cations of  these  three. 

In  the  first  method  the  dye  solution  is  mixed  and  pre- 
cipitated simultaneously  with  the  base  and  then  fixed. 

In  the  second  method  the  dye  is  precipitated  on  the 
base  which  has  already  been  made  and  then  fixed. 

In  the  third  method,  generally  used  in  the  case  of  the 
insoluble  or  pulp  colors,  the  dye  in  the  form  of  a  water 
paste  and  the  base  are  mechanically  mixed  together  by 
grinding. 

In  these  different  methods  the  hue  of  the  color  can  be 
varied  by  using  different  strengths  of  solutions,  different 


PROPERTIES  OF  INK-MAKING  MATERIALS  85 

temperatures,  different  amounts  of  grinding  and  in  some 
cases  different  precipitating  or  fixing  agents.  Of  course 
for  the  various  classes  of  dyes  various  precipitating  agents 
are  employed  and  it  is  a  little  beyond  the  scope  of  this 
work  to  enter  into  details  regarding  them.  The  general 
methods  of  precipitating  and  preparing  these  different 
classes  of  lakes,  however,  are  as  follows: 

In  the  first  case  a  solution  of  a  certain  salt  of  the 
carrier  is  made,  the  dye  mixed  in  and  the  precipitating 
agent  added  with  constant  stirring.  Thus  in  the  case  of 
a  dye  to  be  made  on  an  aluminum  hydrate  and  artifical 
barytes  base,  a  solution  of  aluminum  sulphate  is  made 
and  a  solution  of  calcined  carbonate  of  soda  is  run  into 
it,  followed  by  the  dye  solution.  Barium  chloride  is 
then  added  to  the  whole  and  the  dye  is  precipitated  and 
fixed.  The  more  stirring  the  lake  is  given  at  this  point 
the  firmer  it  will  be  fixed.  If,  however,  there  is  any 
unprecipitated  coloring  matter,  more  barium  chloride  is 
added.  It  is  usual  to  add  the  precipitating  agent  hi 
excess,  as  an  excess  helps  in  fixing  the  dye. 

The  different  hues  of  these  and  the  second  class  of 
lakes  also  are  obtained  by  a  variety  of  methods  jealously 
guarded  by  the  various  manufacturers,  the  most  common 
of  which  are  different  strengths  of  solution,  different 
temperatures  either  of  the  precipitating  solution  or  of 
the  solution  after  precipitation  and  by  mixing  a  small 
amount  of  another  dye  in  the  solution.  The  first  two 
of  these  methods  also  exert  an  influence  on  the  working 
qualities  of  the  lake,  as  the  temperature  and  strength 
of  the  solutions  have  a  great  deal  of  influence  on  the 
physical  characteristics  of  the  base. 

In  the  second  case  the  carrier  is  made  into  a  thin 


86         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

paste  with  water,  the  dye  solution  added  and,  after  a 
thorough  mixing,  the  precipitating  solution  is  run  in. 
Some  of  these  lakes,  notably  those  precipitated  with 
tannin,  require  the  use  of  a  fixative  such  as  tartar 
emetic. 

The  third  class  comprises  the  insoluble  azo  colors, 
which  are  generally  sold  in  the  form  of  a  paste  or  pulp. 
These  dyes  can  be  ground  directly  into  the  carrier  on  the 
mill  or  the  dye  and  carrier  can  be  mixed  to  a  thin  con- 
sistency and  stirred  into  each  other,  barium  chloride 
added  and  the  whole  boiled.  This  develops  certain 
changes  of  hue  in  some  cases  and  also  serves  to  fix  the 
dyes  that  are  at  all  soluble  in  water.  Of  course  where 
desired  the  base  may  be  precipitated  at  the  time  the  dye 
is  poured  in.  In  some  cases  the  dye  will  not  stand  boil- 
ing with  barium  chloride  so  that  the  precipitation  must 
be  made  in  the  cold.  The  use  of  calcium  chloride  and 
lead  acetate  as  developers  instead  of  barium  chloride  will 
give  variations  in  the  hues  of  certain  colors. 

An  advantage  that  these  pulp  colors  also  have  is  that 
they  can  be  mixed  with  the  proper  base  and  varnishes 
and  ground  directly  into  printing  ink  on  a  roller  mill, 
the  water  being  pressed  out  in  the  grinding.  In  plate 
printing  inks  the  question  of  the  base  for  organic  lakes 
is  not  of  great  importance  but  for  typographic  inks,  only 
those  lakes  made  on  a  precipitated  base,  such  as  alumi- 
num hydrate,  blanc  fixe,  lithopone,  etc.,  should  be  used. 
A  full  discussion  of  the  various  bases  and  their  value  as 
ink-making  materials  will  be  found  in  a  preceding  chapter. 
In  general  the  precipitating  agents  employed  in  manu- 
facturing organic  lakes  are  barium  chloride,  lead"  salts, 
aluminum  oxide,  tin  salts  and  tannic  acid. 


PROPERTIES  OF  INK-MAKING  MATERIALS  87 

In  the  past  very  nearly  all  the  organic  lakes,  that  were 
not  to  a  great  extent  soluble  in  oil  varnish,  were  used 
as  printing  ink  colors  and  many,  even  those  bleeding  in 
oil  and  being  fugitive  to  light,  which  should  have  barred 
them  entirely,  were  used.  This  was  especially  true  of 
aniline  lakes  which  even  now  for  this  reason  bear  a  very 
bad  reputation  in  regard  to  fading  and  bleeding.  The 
wide  use  of  these  inferior  lakes  was  in  great  part  due  to 
their  superior  working  qualities  and  to  the  fact  that  they 
gave  bright  and  fiery  colors  and  hues  that  could  not  be 
duplicated  or  even  approximated  in  the  available  mineral 
pigments. 

The  use  of  these  unsuitable  lakes  is  now  rapidly 
decreasing,  and  their  place  has  been  taken  by  the  per- 
manent non-bleeding  lakes,  most  of  which  are  made 
from  insoluble  azo  dyes.  As  a  rule  all  the  lakes  made 
from  diazo-dyes,  whether  the  dye  is  soluble  or  not,  are 
permanent  both  to  light  and  atmospheric  conditions  and 
do  not  dissolve  in  any  of  the  mediums  used  in  printing. 
These  colors  are  in  fact  more  permanent  than  any  of  the 
mineral  colors  and  are  infinitely  superior  to  them  in 
working  qualities.  They  can  be  obtained  moreover  in 
almost  every  color  and  hue.  The  organic  lakes  can  also 
be  made  to  give  a  series  of  very  transparent  inks,  a  thing 
impossible  with  the  mineral  colors. 

Inks  made  from  the  organic  lake  pigments  are  abso- 
lutely essential  to  the  three-color  process,  as  the  colors 
necessary  to  produce  a  properly  blended  print,  from  the 
three  plates,  in  which  all  the  lights  and  shades  have  their 
true  color  value,  can  only  be  made  from  these  pigments; 
there  being  no  mineral  pigments  that  will  give  the  proper 
hues  of  red,  yellow  and  blue. 


88         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

It  is  almost  impossible,  in  view  of  the  fact  that  these 
lakes  are  sold  under  different  trade  names  by  the  various 
manufacturers  and  jobbers,  to  give  any  list  of  colors  that 
would  be  suitable  for  use  and  the  only  method  open  to 
the  printing  ink  chemist  in  determining  the  value  of  a 
lake  is  to  determine  if  possible  the  dye  used  in  making 
the  lake,  what  the  base  of  the  lake  is  and  to  practically 
try  out  the  lake  itself  for  fading,  bleeding  and  working 
qualities  under  the  scheme  already  outlined. 

An  illustration  of  the  difficulties  in  the  way  of  giving 
any  definite  tables  or  descriptions  of  the  different  lakes 
is  shown  by  the  fact  that  lakes  of  the  same  color  and  hue 
made  from  the  same  dye  will  be  found  on  the  market 
under  perhaps  a  half  a  dozen  different  trade  names  or 
numbers.  Thus  a  red  called  "Scarlet  Lake"  by  one 
manufacturer  may  be  exactly  like  the  " Brilliant  Scarlet" 
of  another  manufacturer.  On  the  other  hand  there  is 
no  assurance  that  the  lakes  sold  by  two  manufacturers 
under  the  same  name  will  be  the  same  hue  or  even  if 
they  have  the  same  color  and  hue  approximately,  it  does 
not  follow  that  they  have  been  made  from  the  same  dye 
or  in  the  same  manner.  One  of  the  lakes  may  be  satis- 
factory in  every  respect,  while  the  other  may  be  a  very 
poor  color. 

SECTION   TWO.     OILS 

LINSEED  OIL 

While  there  has  been  a  great  deal  of  literature  written 
concerning  linseed  oil,  there  is  still  much  work  to  be  done 
in  order  to  give  the  technical  chemist  engaged  in  manu- 
facturing and  using  it,  a  broad  enough  knowledge  for 
him  to  do  his  work  to  the  most  economical  advantage. 


PROPERTIES  OF  INK-MAKING  MATERIALS  89 

There  are  very  many  problems  that  are  constantly  arising 
in  practical  work  with  linseed  oil,  to  solve  which,  the  tech- 
nical chemist  must  blindly  grope  and  there  are  many 
questions  purely  chemical  relating  to  the  testing  and 
identification  of  this  material  that  are  at  present  mys- 
teries. The  old  system  of  constants  has  proved  entirely 
inadequate  to  differentiate  between  oils  treated  by  air 
blowing  or  ageing,  and  adulterated  oils.  Further  there 
are  no  definite  ways  of  determining  the  specific  nature  of 
the  adulteration  even  if  adulteration  can  be  proved  as 
existing. 

The  authors  have  done  a  great  deal  of  work  along  these 
lines  but  as  the  field  has  proven  to  be  so  broad  they  can- 
not, at  this  time  put  forth  any  theories  or  deductions; 
they  are,  however,  convinced  that  the  constitution  of 
linseed  oil  is  far  more  complex  and  is  affected  by  many 
more  conditions  than  the  investigators  heretofore  have 
imagined. 

Linseed  oil  comes  on  the  market  in  a  number  of  dif- 
ferent grades  depending  on  the  quality  of  the  seed,  the 
climatic  conditions  under  which  the  seed  was  grown,  the 
amount  of  admixture  of  foreign  seed,  the  process  of  extrac- 
tion, the  length  of  time  it  has  been  stored,  the  method  of 
treatment  if  the  oil  has  been  refined,  and  the  honesty  of 
those  who  have  handled  it  either  as  crushers  or  jobbers. 
These  conditions  cause  the  physical  and  chemical  con- 
stants of  the  oils  produced  to  vary  greatly  and  also  affect 
their  behavior  when  used  for  various  purposes.  The 
wide  variation  in  chemical  and  physical  constants  from 
the  above  causes,  coupled  with  the  introduction  of  cer- 
tain drying  oils  which  have  lately  come  on  the  market, 
and  new  methods  of  treating  non-drying  oils,  has  made 


go         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

it  very  difficult  to  determine  positively  whether  an  oil 
has  been  adulterated  or  not. 

The   accepted    constants   for   raw   linseed    oil    are    as 
follows: 

Not  under  .931 
Not  under  170 


Specific  Gravity 
Iodine  Value 


Saponification  Number 
Flash 


About  190 

Not  under  280°  C. 


As  stated  before,  the  constants  are  influenced  by  a 
number  of  things  and  the  fact  that  an  oil  meets  the 
above  requirements,  or  even  falls  below  them  to  some 
extent,  is  no  criterion  either  of  its  purity  or  of  its  adul- 
teration. 

The  simple  treatment  of  blowing  air  through  the  oil  at 
a  temperature  of  about  100°  C.  changes  these  constants 
and  at  the  same  time  changes  the  odor  and  color  of  the 
oil  completely.  Absolutely  pure,  raw  linseed  oil  blown 
at  100°  C.  without  any  addition  of  drier  or  other  treat- 
ment, has  failed  to  pass  the  above  specification  while  a 
fresh  pressed  oil  adulterated  with  soya  bean  oil  and  one 
adulterated  with  blown  rape  seed  oil  have  been  found  to 
meet  these  requirements.  The  following  table  shows  the 
result  of  blowing  a  pure  linseed  oil  direct  from  the 
crusher. 


Before 
blowing 

Blown  for 
4hrs. 

Blown  for 
18  hrs. 

Blown  for 
27  hrs. 

Specific  Gravity  

.9355 

.9360 

.940 

.946 

Iodine  Value 

184.5 

181.4 

1794 

161  6 

Acid  Value  
Saponification  Number  
Flash  

1.0 
193.2 
282 

1.18 
193.3 
284 

1.18 
192.9 
282 

1.18 
192.7 
280 

PROPERTIES  OF  INK-MAKING  MATERIALS 


The  viscosity  was  of  course  increased  in  proportion. 

The  figures  given  below  are  those  of  oils  adulterated 
in  one  case  with  10  per  cent  of  blown  rape  seed  oil  and 
in  the  other  case  with  20  per  cent  of  soya  bean  oil: 


Oil  as 
received 

With  10% 
blown  rape 
seed  oil 

Oil  as 
received 

With  20% 
soya  bean 
oil 

Specific  Gravity 

.9356 

9378 

9325 

931 

Iodine  Value 

1784 

170 

181  3 

1706 

Acid  Value 

1  53 

2  2 

90 

93 

Saponification  Number  
Flash.  . 

194.3 
295 

194.8 
295 

193 
296 

192.7 
295 

The  separation  of  a  flocculent  mass  on  heating  an  oil 
to  between  270°  C.  and  300°  C.,  known  as  breaking,  has 
been  found  by  the  authors  to  be  a  very  erratic  thing. 
Rapidity  of  heating  is  a  great  factor;  an  oil  heated  in  a 
test  tube  where  the  rise  is  very  rapid  will  show  a  break 
whereas  the  same  oil  heated  slowly  will  not.  All  raw 
linseed  oils,  if  heated  rapidly  enough,  can  be  made  to 
show  a  break  even  though  the  oil  is  bright  and  clear 
and  has  been  allowed  to  settle  for  six  months.  The 
breaking  can,  however,  be  eliminated  even  from  a  freshly 
pressed  oil  by  simply  warming  the  oil  at  75°  C.  for  a 
couple  of  hours.  This  heating  is  attended  by  no  change 
in  the  physical  or  chemical  constants  of  the  oil. 

As  a  general  rule  raw  linseed  oil  will  separate  out  a 
flocculent  precipitate  on  being  chilled  which  will  disappear 
on  warming.  When  oil  has  been  heated  to  100°  C.  and 
air  blown  through  it,  this  separation  does  not  take  place 
on  chilling. 

Raw  linseed  oil,  as  it  comes  from  the  crusher  is  not 


92          CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 

well  adapted  to  the  economical  manufacture  of  printing 
ink  varnishes.  All  raw  linseed  oils  to  be  so  used,  should 
be  subjected  to  a  previous  treatment.  The  most  satis- 
factory treatment  has  been  found  to  be  the  blowing  of  the 
oil,  heated  to  100°  C.,  with  air.  This  treatment  will 
produce  a  fine,  clear,  odorless  oil  of  high  viscosity  and 
gravity  and  is  attended  with  no  loss  of  weight.  The 
method  of  blowing  is  merely  to  raise  the  oil  to  100°  C. 
by  means  of  a  steam  jacketed  kettle  or  steam  coil,  and  as 
this  temperature  is  easily  reached,  exhaust  steam  should 
be  used  for  economical  reasons.  The  air  is  then  blown 
through  the  oil  in  a  number  of  fine  jets  until  the  oil  has 
reached  the  proper  viscosity  which  we  have  found  to  be 
between  1600  and  2000  on  an  Engler  viscosimeter,  water 
being  taken  as  100. 

Oil  of  this  viscosity  will  take  much  less  time  to  boil 
or  burn  to  the  different  grades  of  plate  and  varnish  oils 
and  will  show  far  less  loss  in  the  burning  or  boiling.  A 
comparison  between  the  loss  of  weight  and  time  of  burn- 
ing to  medium  plate  oil  between  an  unblown  oil  and  the 
same  oil  blown  to  a  viscosity  of  1600  is  herewith  given: 


Unblown  Oil 

Blown  Oil 

Viscosity  at  start 

747 

1600 

Time  of  burning  

40  minutes 

20  minutes 

Loss  in  weight 

18% 

6% 

These  oils  were  burnt  to  the  same  viscosity  and  gravity. 
The  raw  oil  used  was  of  a  light  yellow  color,  with  consider- 
able turbidity  and  a  heavy  malt  odor,  while  the  blown  oil 
was  of  a  rich  mahogany  color  without  turbidity  or  odor. 
The  burnt  oil  made  from  the  unblown  oil  was  of  a  greenish 


PROPERTIES  OF  INK-MAKING  MATERIALS  93 

color,  full  of  soot,  while  that  made  from  the  blown  oil  was 
of  a  reddish  cast,  approximately  free  from  carbon.  This 
treatment  of  the  raw  oil  has  been  found  entirely  sufficient 
and  no  other  treatment  is  recommended.  The  color  of 
the  oil  after  blowing  we  have  found  to  vary  greatly,  some 
oils  becoming  very  light  in  this  treatment  while  others 
darken  considerably,  this  being  no  doubt  due  to  the 
different  sources  of  seeds. 

LINSEED  PLATE  OILS 

In  making  printing  ink  vehicles,  two  methods  may  be 
pursued;  namely  boiling  and  burning  the  oil  to  the 
proper  consistency.  If  oil  is  blown  long  enough  it  will 
become  the  proper  consistency  but  practical  trials  of  plate 
printing  oils  made  in  this  way  have  shown  that  the  oil  so 
made  is  not  satisfactory,  having  a  false  body  and  being 
too  soft.  The  results  obtained  by  blowing  are  purely 
the  results  of  oxidation  while  the  authors  have  proved 
that  both  oxidation  and  polymerization  are  necessary  to 
make  a  satisfactory  working  plate  ink  oil  or  varnish 
and  that  this  result  is  only  obtained  by  the  use  of  high 
temperature.  Heavy  blown  oils  are,  however,  used  to  a 
large  extent  in  typographic  inks. 

Plate  oils  are  generally  made  in  three  consistencies, 
strong,  medium  and  weak,  and  require  less  tack  and 
length  than  typographic  va'rnishes  and  yield  no  gloss 
on  drying  in  the  ink.  They  are  therefore  made  from 
linseed  oil  alone  without  other  additions.  Since  the  be- 
ginning of  the  art,  the  oils  for  use  in  plate  inks  have 
been  burned  in  iron  pots  to  the  desired  thickness  in  the 
following  manner. 

The  oil  is  put  in  an  iron  pot  holding  about  5  gallons 


94         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

and  heated  to  about  160°  C.  It  is  then  ignited  by  means 
of  a  red  hot  ladle  and  allowed  to  burn  with  enough 
stirring  to  thoroughly  mix  the  oil  and  to  keep  the  heat 
from  becoming  excessive;  too  much - stirring  will,  how- 
ever, extinguish  the  pot.  The  time  required  to  burn 
light  oil  is  about  15  to  20  minutes,  depending  on  the 
initial  viscosity  of  the  oil.  Medium  oil  is  burnt  from 
25  to  45  minutes,  while  the  heavy  or  strong  oil  is 
burnt  from  2  to  3  hours.  On  account  of  the  length  of 
time  required  for  the  burning  of  this  strength  of  oil  and 
the  consequent  heat  developed,  the  burner  has  to  keep 
the  heat  down  by  adding  from  time  to  time  small  amounts 
of  cold  oil. 

The  light  oil  loses  in  this  process  from  5  per  cent  to 
10  per  cent  of  its  weight;  the  medium  oil  from  8  per  cent 
to  1 8  per  cent  and  the  strong  oil  from  18  per  cent  to 
25  per  cent.  As  can  readily  be  seen,  this  great  loss  is 
principally  due  to  the  use  of  the  oil  itself  as  a  fuel,  which 
is  a  very  costly  process.  It  has  always  been  traditional 
that  this  burning  was  necessary  to  burn  the  grease  out 
of  the  oil;  and  the  belief  was  founded,  no  doubt,  on  the 
fact  that  a  burnt  oil  will  not  leave  a  grease  mark  on 
paper.  This  is,  of  course,  due  to  the  fact  that  burnt 
oils  have  a  higher  viscosity  and  gravity  and  do  not  spread 
and  penetrate  the  fibers  of  the  paper. 

The  burning  of  the  oil  is  not  at  all  necessary  and  the 
polymerization  and  oxidation  required  can  be  effected 
as  well  by  outside  heat,  by  rapidly  raising  the  tempera- 
ture of  the  oil  to  about  320°  C.  and  holding  it  there  until 
the  oil  has  reached  the  proper  viscosity  and  gravity. 
This  process  which,  instead  of  utilizing  the  oil  itself  as 
fuel,  makes  use  of  the  cheaper  heating  mediums  such  as 


PROPERTIES  OF  INK-MAKING  MATERIALS  95 

gas,  coal  or  electricity  and  shows  a  very  small  loss  in  the 
oil.  The  maximum  loss  for  medium  oil  being  2  per  cent 
and  for  strong  oil  5  per  cent,  thus  making  production 
of  plate  oils  a  great  deal  cheaper.  Moreover  the  oils 
made  in  this  way  are  transparent,  of  much  better  color 
and  lack  the  disagreeable  empyreumatic  odor  of  the 
burnt  oils;  they  are  also  entirely  free  from  carbon  and 
contain  a  much  lower  percentage  of  free  fatty  acids. 

It  has  continually  been  contended  that  the  oils  made 
in  this  way  were  not  suitable  for  plate  inks  but  the 
authors  have  proved  that  this  is  not  the  case.  Plate 
oils  made  by  this  process  have  been  used  by  us  prac- 
tically and  on  a  large  scale  and  the  ink  made  from  them 
has  shown  superior  working  qualities  to  the  inks  made 
from  the  old  process  burnt  oils. 

The  apparatus  shown  in  figure  5  was  designed  by  the 
authors  with  a  view  to  preventing  the  oils  from  acci- 
dently  boiling  over,  to  keep  the  loss  to  a  minimum  and 
to  carry  away  the  obnoxious  fumes  arising  in  the  process. 
Electrical  heat  was  employed  on  account  of  its  economy, 
the  niceness  of  control  possible  with  it  and  because  it 
obviates  the  danger  of  fire. 

SOYA  BEAN  OIL 

The  only  oil  that,  at  present,  in  any  way  compares  with 
linseed  oil  as  a  drying  oil  for  use  in  printing  inks,  is 
soya  bean  oil.  This  oil  dries  a  little  slower  than  linseed 
oil  and  when  dried  exhibits  a  film  not  quite  so  hard  and 
durable  but  more  elastic  than  that  from  linseed  oil. 
The  authors  found  that  inks  made  from  soya  bean  oils 
and  varnishes  were  almost  similar  in  working  qualities 
and  appearance  to  those  made  with  similar  linseed  oil 


96         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

vehicles  but  were  just  a  trifle  softer  and  more  greasy. 
These  inks,  which  were  made  with  drier,  dried  about  as 
well  as  linseed  oil  inks.  Soya  bean  plate  oils  and  typo- 
graphical varnishes  can  be  used  as  substitutes  for  linseed 


FIGURE  5.  —  APPARATUS  FOR  MAKING  PRINTING  INK  VARNISHES. 

oil  varnishes,  except  for  the  highest  grade  of  work.  In 
making  printing  ink  oils  and  varnishes  from  soya  bean 
oil,  the  same  processes  are  used  as  are  employed  for 
making  linseed  oil  plate  oils  and  varnishes. 


PROPERTIES  OF  INK-MAKING  MATERIALS  97 

Soya  bean  oil  is  pressed  from  the  soya  bean,  originally 
a  native  of  China  and  Manchuria  but  now  grown  through- 
out the  world  for  fodder.  In  this  country  it  is  widely 
grown  for  feeding  purposes  but  as  yet  no  attempts  have 
been  made  to  crush  the  beans  for  oil.  Its  constants  are 
somewhat  lower  than  those  of  linseed  oil  and  samples 
from  different  sources  show  great  variations.  Up  to  the 
present  time  there  has  been  very  little  published  about 
soya  bean  oil,  as  its  introduction  as  a  competitor  to  lin- 
seed oil  has  occurred  within  the  last  few  years. 

Samples  analyzed  by  the  authors  gave  the  following 
range  of  constants: 

Specific  Gravity 9240  to       .9270 

Acid  Value 70     to      5.2 

Iodine  Value 124.5       to  148.6 

Saponification  Number 192.8       to  194 

ROSIN  OIL 

Rosin  oil  and  rosin  oil  varnishes  are  very  important 
ink-making  vehicles,  there  use,  however,  being  restricted 
to  the  typographic  inks.  They  are  generally  used  as 
substitutes  for  linseed  oil  varnishes  for  the  cheaper 
grades  of  ink,  but  are  sometines  used  with  linseed  var- 
nishes in  high  grade  inks  to  impart  some  special  property 
or  to  meet  some  special  condition  of  work. 

Rosin  oil,  of  itself,  is  a  non-drying  oil,  drying  when 
used  in  inks  only  by  absorption  into  the  paper  but  when 
boiled  with  certain  driers  it  forms  an  oil  that  dries 
fairly  well.  In  combination  with  rosin  it  makes  a  good 
substitute  for  gum  varnishes. 

Rosin  oil  is  obtained  by  subjecting  colophony  to  de- 
structive distillation  and  is  separated  by  fractionation 


98         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

into  four  different  runs  of  different  consistency  and 
gravity.  The  first  run  is  the  lightest  while  the  fourth 
run  is  a  heavy,  thick,  tacky  oil  of  about  the  same  con- 
sistency as  strong  linseed  plate  oil  or  No.  4  lithographic 
varnish. 

PARAFFINE  OIL 

Paraffine  oil  is  a  distillate  from  the  residues  of  crude 
petroleum  with  a  specific  gravity  of  from  .800  to  .820. 
It  is  largely  used  as  a  vehicle  for  cheap  inks.  It  has  no 
drying  properties  whatever  except  by  being  absorbed 
into  the  paper.  Paraffine  oil  is  also  largely  used  in  mak- 
ing various  special  varnishes. 

KEROSENE  OIL 

Kerosene  oil,  in  connection  with  some  long  varnish,  is 
used  as  a  vehicle  for  very  cheap  inks  for  use  on  news- 
papers. 

TYPOGRAPHIC  VARNISHES 

A.  Linseed  Oil  Varnishes.  —  The  principal  typo- 
graphic varnishes  are  made  from  burnt  or  boiled  linseed 
oil  and  come  on  the  market  in  a  number  of  grades  of 
consistency  that  can  be  mixed  into  combinations  to  suit 
the  character  of  work  for  which  the  ink  is  to  be  used, 
and  the  physical  characteristics  of  the  dry  color  em- 
ployed. 

The  linseed  oil  varnishes  range  in  consistency  from  a 
thin  varnish,  a  little  heavier  than  raw  linseed  oil,  and  with 
about  the  same  drying  properties  as  a  painter's  boiled 
oil,  to  one  so  heavy  that  it  will  not  flow  till  warmed  and 
which  dries  very  rapidly.  The  heavy  lithographic  var- 
nishes of  linseed  oil  are  very  tacky.  The  varnishes  are 


PROPERTIES  OF  INK-MAKING  MATERIALS  99 

sold  by  numbers  according  to  their  tack,  viscosity,  gravity 
and  drying  qualities.  The  thin  varnishes  range  from  oooo 
to  o  and  the  heavy  ones  from  i  to  8.  These  varnishes 
are  made  in  the  same  way  as  plate  oils  either  by  burning 
or  boiling  the  oil  to  the  proper  consistency,  tack  and 
drying  properties.  In  some  cases  for  the  more  rapid 
drying  grades  a  drier  is  added  such  as  borate  of  man- 
ganese, red  lead  or  a  metallic  soap  of  rosin,  linseed  oil 
or  tung  oil. 

A  varnish  of  high  gravity  but  of  little  viscosity  can  be 
made  by  air-blowing  linseed  oil  at  100°  C.;  this  oil  is 
soft  and  buttery  and  has  a  soft  body  that  makes  the  ink 
stand  up  without  being  tacky.  This  together  with  the 
fact  that  it  is  slow  drying  makes  it  an  ideal  vehicle  for 
offset  inks. 

It  can  readily  be  seen  that  it  is  possible  by  judicious 
blending  of  these  varnishes  to  produce  inks  of  the  right 
degree  of  tack,  softness  and  drying  properties  for  any 
purpose  or  process. 

B.  Gum  Varnishes.  —  Gum  varnishes  are  made  from 
certain  gum  resins,  most   commonly  damar  and   kauri. 
These  are  melted  and  mixed  with  linseed  oil  heated  to  a 
high  temperature  with  or  without  the  addition  of  driers; 
this  depending  on  whether  a  quick  drying  or  moderate 
drying   varnish   is   desired.     These   varnishes   give   gloss 
to  the  printed  work  and  a  heavy  body  and  great  tack 
to  the  ink.     Inks  made  with  them   stand  up   well   on 
the  paper  and  dry  extremely  hard.     Gum  varnishes  are 
always  used  in  combination  with  other  varnishes. 

C.  Rosin    Oil   Varnishes.  —  Rosin    oil  varnishes    are 
made  by  heating  rosin   oil  up  to  360°    C.  and  adding 
either  borate  of  manganese,  red  lead  or  a  metallic  soap 


ioo        CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

of  rosin.  These  rosin  oil  varnishes  can  be  used  in 
place  of  the  linseed  oil  varnishes  for  the  cheaper  grades 
of  ink. 

There  is  also  a  gum  varnish  substitute  made  by  dis- 
solving rosin  in  rosin  oil  which  is  known  also  as  rosin  oil 
varnish.  In  very  cheap  work  a  varnish  made  from  par- 
affine  oil  and  rosin  can  be  used  in  place  of  rosin  varnish. 
When  properly  made  this  varnish  gives  good  results  and 
is  quite  cheap. 

D.  Long  Varnishes.  —  There  are  certain  varnishes 
made  from  combinations  of  asphaltum,  rosin,  stearine 
pitch,  paraffine  oil,  wood  tar  and  kerosene  oil  that  are 
known  as  long  varnishes  on  account  of  their  length  and 
tack.  Different  amounts  and  combinations  of  the  above 
materials  give  varnishes  of  different  degrees  of  tack  and 
length.  These  varnishes  are  particularly  valuable  when 
it  is  necessary  to  use  a  pigment  which  in  itself  is  short. 
Being  dark  in  color  they  cannot  be  used  except  for  black 
or  darkly  colored  inks. 

REDUCERS  AND  MISCELLANEOUS  MATERIALS 

A.  Asphaltum.  —  The  asphal turns  are  natural  hydro- 
carbons which  occur  in  several  forms,  the  principal  differ- 
ences being  in  their  melting  points.  Asphaltum  is  a 
brilliant,  black  material  with  a  distinctly  brown  under 
hue.  As  a  rule  it  is  hard  at  ordinary  temperatures  but 
there  are  several  varieties  that  are  semi-liquid.  Besides 
being  used  for  varnish  making,  it  is  also  used  to  some 
extent  in  the  manufacture  of  duo-tone  inks,  where  its 
brown  under  hue  is  taken  advantage  of. 

Asphaltum  is  also  used  in  preparing  lithographic  plates 


PROPERTIES  OF  INK-MAKING  MATERIALS  101 

and  in  making  transfer  inks.  It  is  readily  soluble  in  all 
the  common  solvents  and  is  taken  up  easily  when  heated 
with  paraffine  oil  or  kerosene. 

B.  Petrolatum.  —  Petrolatum  is  useful  for  making  an 
ink  run  smoothly  on  the  press,  to  correct  fast  drying  in 
inks  that  must  have  a  heavy  consistency,  to  take  out 
tack  and  to  shorten  inks  that  are  too  long. 

C.  Soap.  —  Soap    is    also    used    to    make    inks  work 
smoothly,  to  shorten  naturally  long  inks  and  to  give  better 
distribution. 

D.  Lanolin.  —  Lanolin  or  purified  wool  grease  will  also 
answer  the  same  purpose  as  soap  but  is  a  little  more 
sticky. 

E.  Miscellaneous  Materials.  —  Beeswax,    spermaceti, 
carnauba  wax,  paraffine  wax,  oil  of  lavender,  venice  tur- 
pentine,   balsam    fir,    balsam    of    copaiba,    gum    mastic, 
stearic  acid  and  olive  oil  are  also  used  to  some  extent  in 
making   specialities   for   imparting   certain   properties   to 
inks    but    they    are    mostly    used    in    making    different 
kinds  of  transfer  inks  and  preparations  for  lithographic 
work. 

F.  Reducers.  —  For  reducers  to  make  stiff  inks  thin, 
particularly   lithographic   and   offset   inks,   and   to   keep 
inks  from   drying  too   fast  the   following  materials   are 
generally  used: 

The  very  thin  grades  of  linseed  oil  varnish. 

Rosin  oil     (particularly  to  correct  fast  drying). 

Paraffine  oil. 

Kerosene  oil. 

Amyl  acetate. 

Ether. 

Oleic  acid.  :  ;  >  '  « '»  >' 


102       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

The  last  three  are  particularly  used  in  offset  work;  they 
should  however  be  used  sparingly. 

Ether  and  amyl  acetate  are  used  because  they  are 
volatile,  the  theory  being  that  they  thin  the  ink  in  the 
fountain  but  volatilize  by  the  time  they  reach  the  work, 
thus  giving  an  impression  that  consists  mostly  of  pig- 
ment and  therefore  has  more  color.  That  these  materials 
really  accomplish  this  effect  is  extremely  doubtful. 

Oleic  acid  is  supposed  to  assist  in  preserving  the  work 
on  the  plate.  It  is  used  in  very  small  quantities,  a  few 
drops  to  a  fountain  full  of  ink. 

DRIERS 

The  principal  driers  used  in  printing  inks  are  the 
straight  metallic  driers,  such  as  borate  of  manganese  and 
red  lead,  the  metallic  soap  driers  which  consist  of  the 
resinates,  linolates  and  tungates  of  lead  and  manganese 
dissolved  in  linseed  oil,  and  the  japan  driers,  which 
consist  of  a  varnish  gum  and  one  of  the  metallic  soap 
driers  dissolved  in  linseed  oil  and  thinned  with  turpentine. 

The  first  class  of  driers  are  used  principally  in  plate 
inks  and  they  are  generally  worked  into  a  paste  with 
linseed  oil  and  paris  white. 

The  resinates,  linolates  and  tungates  can  be  made  in 
two  ways  either  by  saponifying  the  rosin  or  oils,  pre- 
cipitating the  acids  with  sulphuric  acid  and  saturating 
the  free  acids  with  lead  or  manganese  carbonate  or  by 
precipitating  the  soap  solution  directly  with  a  solution 
of  lead  nitrate  or  manganese  sulphate.  The  soap  driers 
and  japan  driers  are  generally  used  exclusively  in  typo- 
graphic./work. 


PROPERTIES  OF  INK-MAKING  MATERIALS  103 

There  are  a  number  of  patented  and  special  driers  on 
the  market  but  it  is  unnecessary  to  mention  them  here 
as  they  are  merely  modifications  in  some  way  of  the 
three  classes  of  driers  mentioned  above  and  any  work 
claimed  for  them  can  be  done  by  the  above  mentioned 
driers  just  as  well. 


PART   THREE 

SECTION    ONE.     THE    MANUFACTURE    OF 
PRINTING   INK 

GENERAL  CONSIDERATIONS 

IN  the  manufacture  of  printing  ink  there  are  four  gen- 
eral essentials  for  producing  good  inks. 

First,  the  material  should  be  properly  proportioned, 
that  is,  the  pigments  should  be  carefully  weighed  out  so 
as  to  make  the  color  desired  directly,  without  additions, 
and  this  can  generally.be  done  if  a  formula  is  worked  up 
in  a  small  way  in  a  laboratory.  The  vehicles  should 
always  be  carefully  weighed  with  the  error  on  the  side 
of  stiffness  rather  than  softness,  as  it  is  easier  to  make  a 
stiff  ink  soft  than  to  stiffen  up  a  soft  ink,  as  the  latter 
requires  the  addition  of  dry  pigment  and  this  is  very 
troublesome,  especially  if  the  color  is  a  mixture  of  two  or 
more  pigments.  In  this  case  there  will  always  be  some 
difficulty  in  matching  the  color.  It  might  be  noted  that 
many  colors  which  seem  stiff  when  mixed  will  be  a  great 
deal  softer  after  running  through  the  mills.  In  these 
cases  experience  must  be  the  teacher. 

Secondly,  the  materials  must  be  thoroughly  mixed,  every 
particle  of  pigment  be  brought  into  contact  with  the 
varnish  and  the  whole  mass  wet  out  so  that  it  has  a 
uniform  consistency. 


MANUFACTURE  OF  PRINTING  INK  105 

Thirdly,  the  ink  should  be  sufficiently  ground  to  get 
the  necessary  homogeneity  and  smoothness.  AS  will  be 
stated  later,  some  inks  from  the  nature  of  the  pigment 
used  and  the  kind  of  work  the  ink  is  going  to  be  used 
on,  require  more  grinding  than  others.  Typographic 
inks,  especially,  should  be  ground  to  a  great  degree  of 
fineness  and  smoothness.  In  using  roller  mills,  care 
should  always  be  taken  to  cut  off  the  ink  that  runs  to 
the  edges  and  return  it  to  the  hopper  to  be  reground. 

Fourthly,  all  inks,  after  coming  from  the  mills  should 
be  blended;  that  is  remixed,  so  that  the  color  will  be 
uniform.  This  is  particularly  necessary  in  inks  that  are 
made  from  two  or  more  pigments  and  for  pigments  that 
have  any  tendency  to  work  away  from  the  oil.  Correc- 
tions in  the  hue  or  consistency  of  the  inks  should  be  made 
at  the  time  of  blending.  For  the  purpose  of  correcting 
the  hue  a  set  of  stock  inks  consisting  of  the  various  pig- 
ments ground  in  oil  or  varnish  should  be  kept  on  hand. 
The  addition  of  these  will  bring  the  ink  to  the  proper 
hue  and  consistency  at  the  same  time  and  obviate  the 
necessity  of  regrinding  the  batch,  which  would  be  neces- 
sary if  dry  pigments  were  added.  In  correcting  the  hue 
of  inks  it  should  be  remembered  that  not  only  the  top 
hue  but  also  the  under  hue  should  be  matched.  This 
is  more  important  in  plate  printing  and  halftone  work 
than  it  is  in  general  typographic  work.  The  main  thing 
to  be  considered  in  ordinary  typographic  work  is  top  hue. 

The  weighing  of  the  pigments,  oils  and  varnishes  can 
be  done  on  regular  platform  scales,  the  pigments  being 
weighed  into  rectangular  sheetiron  boxes  fitted  with 
handles  for  lifting.  In  the  case  of  carbon  black,  which  is 
so  light  as  to  make  it  difficult  to  handle,  we  make  the 


io6       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

mixing  of  such  a  size  that  the  material  can  be  dumped 
directly  into  the  mixer  out  of  the  original  bag  it  was 
received  in  without  extra  weighing. 

The  oils  and  varnishes  should  be  stored  in  tanks  fitted 
with  spigots  and  these  materials  run  directly  from  the 


FIGURE  6.  —  MIXER  FOR  MAKING  LARGE  BATCHES  or  INK. 

tanks  into  tared  receptacles  on  the  scales.  These 
receptacles  should  be  of  such  a  design  as  to  allow  the 
vehicle  to  be  entirely  emptied  into  the  mixer  without  loss. 
For  inks  to  be  mixed  in  a  pony  mixer,  the  oils  or  var- 
nishes should  be  weighed  directly  into  the  mixer  cans  and 


MANUFACTURE  OF  PRINTING  INK 


107 


the  pigments  added  when  the  can  is  on  the  mixer.  Care 
should  be  taken  that  all  cans  and  boxes  should  be 
thoroughly  cleaned  before  using.  The  mixing  should  be 
done  on  one  of  two 
regular  types  of  mixers. 
For  large  batches  and 
for  stock  colors,  which 
are  regularly  made  in 
large  amounts,  a  mixer 
of  the  bread  or  dough 
mixer  type  shown  in 
Figure  6  should  be  used. 
These  mixers  should  be 
provided  with  a  close 
fitting  cover  and  a  de- 
vice for  dumping.  The 
authors  have  found  that 
a  mixer  of  this  pattern 
with  gears  on  both  sides, 
driven  by  an  individual 
motor  with  a  noiseless 
chain  drive  are  most 


FIGURE  7.  —  PONY  MIXER. 


satisfactory.  For  small  batches  of  ink  and  odd  colors 
not  regularly  made,  where  frequent  and  thorough  clean- 
ing is  necessary,  the  type  of  pony  mixer  shown  in  Fig- 
ure 7  is  desirable.  This  type  of  mixer  is  also  especially 
adapted  to  blending  batches  of  ink  which  need  correction 
for  hue. 

The  three-roll,  water  cooled,  paint  mill  is  the  best  mill 
for  grinding  inks.  This  mill,  as  shown  in  Figure  8,  con- 
sists of  three  hollow  rolls  of  hard  steely  two  of  which,  the 
outside  ones,  revolve  in  the  same  direction  but  opposite 


108       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

from  the  middle  one;    these  rolls  are  water  cooled  to 
prevent  the  friction  heat  from  affecting  the  ink  and  are 


FIGURE  8.  —  MODERN  THREE  ROLL,  WATER  COOLED  INK  MILL, 
SHOWING  AUTOMATIC  FEEDING  ARRANGEMEMT. 

adjustable  so  that  different  amounts  of  pressure  can  be 
obtained.     The  ink  is  fed  into  the  back  and  middle  rolls 


MANUFACTURE  OF  PRINTING  INK 


109 


between  two  movable  hoppers  and  is  cut  off  from  the 
front  roll  by  a  steel  knife  onto  a  sloping  apron.  The 
knife  edge  should  be  kept  sharp  and  should  always  bear 


FIGURE  9.  —  STONE  MILL  FOR  GRINDING  INK  WHERE  A  GREAT  DEGREE 
OF  FINENESS  is  NOT  REQUIRED. 

true  against  the  roll  throughout  its  whole  length.  The 
rolls  are  geared  so  that  they  revolve  at  different  speeds. 
The  most  satisfactory  way  of  running  the  mills  is  with 
individual  motors  and  noiseless  chain  drives. 

For  grinding  large  quantities  of  plate  inks  to  be  used 


no         CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

on  a  power  press  where  a  great  degree  of  fineness  is  not 
necessary,  a  stone  mill  as  given  in  Figure  9  is  satisfactory. 

EXPLANATION  or  TERMS 

The  following  definitions  of  terms  used  in  the  printing 
trade  to  explain  certain  conditions  arising  in  the  work 
will  serve  to  explain  what  is  meant  when  these  terms 
are  used  in  the  following  pages. 

Striking  Through.  —  When  an  ink  is  very  thin  or  made 
from  a  pigment  that  is  soluble  in  oil,  the  oil  will  penetrate 
through  the  paper,  showing  up  on  the  back  of  the  printed 
sheet  either  a  greasy  mark  or  a  discoloration.  This  is 
due  to  the  penetration  of  the  oil  before  it  has  time  to  dry, 
to  the  fine  particles  of  the  pigment  being  carried  into 
the  paper  by  the  oil  and  to  the  solubility  of  the  pig- 
ment itself  in  the  vehicle.  This  defect  is  called  striking 
through. 

When  work  is  printed  wet,  as  is  often  the  case  in  plate 
printing,  this  striking  through  is  sometimes  due  to  pig- 
ments somewhat  soluble  in  water. 

Bleeding  is  defined  in  a  former  chapter  as  the  solu- 
bility of  a  pigment  in  a  vehicle  or  in  water,  therefore 
when  striking  through  is  due  to  either  of  these  causes  it 
can  be  said  to  be  caused  by  bleeding. 

Offsetting.  —  When  the  ink  from  one  sheet  comes  off 
on  the  back  of  the  sheet  that  is  laid  on  top  of  it,  the  ink 
is  said  to  offset.  There  is  a  method  of  printing  called 
offset  printing  that  will  be  spoken  of  later  on. 

Permanency.  —  This  means  the  resistance  of  an  ink  to 
light,  almospheric  and  chemical  influences. 

Picking  Up.  —  When  the  ink  on  the  plate  or  form  pulls 
out  little  fibers  from  the  paper  it  is  said  to  pick  up. 


MANUFACTURE  OF  PRINTING  INK  III 

Gathering  and  Graining.  —  In  plate  printing,  when  an 
ink  collects  in  little  hard  or  stringy  lumps  on  the  roller  or 
ink  slab  it  is  said  to  gather.  When  the  same  effect  appears 
on  the  rollers  of  a  typographic  press  it  is  called  graining. 

Wiping.  —  The  wiping  of  an  ink  in  plate  printing  is 
the  way  it  acts  when  wiped  off  the  plate  by  the  printer's 
cloth.  After  inking  in  his  plate,  the  printer  takes  a 
starched  cloth  and  wipes  the  superfluous  ink  off.  The 
ink  should  come  off  clean  with  the  cloth  but  should  not 
come  out  of  the  lines. 

Polishing.  —  This  is  the  way  the  ink  leaves  the  plate 
when  the  plate  is  polished  by  the  printer's  hand.  After 
wiping,  there  is  generally  a  thin  film  of  ink  left  on  the 
plate,  and  the  printer  polishes  the  plate  with  his  hand  to 
clean  this  scum  off.  After  polishing,  the  plate  should  be 
perfectly  clean  without  any  film  of  ink  on  it. 

Tints.  —  In  reference  to  color,  the  meaning  of  a  tint 
has  been  explained  in  a  former  chapter  as  a  color  lightened 
with  white.  In  printing  terms  it  is  used  in  a  somewhat 
different  meaning,  namely  to  denote  an  ink  printed  very 
faintly  and  lightly  on  paper. 

Tinting.  —  When  for  any  reason  the  ink  is  taken  up 
on  the  low  parts  of  a  form  or  when  a  plate  ink  has  not 
been  polished  clean  off  the  plate  and  this  causes  a  slight 
discoloration  of  the  whole  impression  it  is  said  to  be 
tinting.  This  can  be  caused  by  a  number  of  things, 
chiefly,  however,  by  the  lint  from  the  paper  filling  up  the 
forms,  and  by  the  use  of  a  gummy  ink  with  a  good  deal 
of  light  varnish  in  it,  which  spreads  over  the  entire  plate 
when  the  press  speeds  up. 

In  the  case  of  plate  inks,  this  is  due  to  a  hard  wiping 
or  greasy  ink. 


112        CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Rubbing  Off.  —  When  a  printed  sheet  is  handled  after 
sufficient  drying  and  the  ink  smears  or  comes  off  on  the 
hand,  it  is  said  to  rub  off. 

Greasy.  —  A  greasy  ink  is  one  that  leaves  a  scum  over 
the  plate  or  form  or  leaves  a  greasy  margin  around  the 
printed  work. 

Greasiness  is  due  to  the  use  of  too  thin  a  vehicle,  too 
thin  an  ink  or  to  the  use  of  a  vehicle  that  does  not  dry 
rapidly  enough  or  to  a  combination  of  all  three  of  these 
defects. 

Duo-Tone  Inks.  —  Duo-tone  inks  are  those  that  show 
a  black  over  hue  and  a  decided  brown  under  hue,  giving 
the  impression  that  the  print  has  been  made  with  two 
printings,  using  different  inks. 

PRINTING  INKS 

Printing  inks  are  divided  into  two  general  classes 
according  to  the  two  basic  processes  of  printing.  These 
two  basic  processes  are  plate  printing,  done  on  intaglio 
plates,  and  typographic  printing,  done  either  from  surface 
plates  such  as  lithographic  plates,  or  raised  plates,  or 
types  such  as  electrotypes  and  lead  types,  where  the  ink- 
taking  surface  is  raised  above  the  body  of  the  plate. 
Of  course  there  are  many  modifications  of  these  two 
processes  in  actual  use  and  the  ink  necessary  for  these 
modifications  varies  with  the  variations  in  the  process. 
Therefore  under  the  head  of  plate  printing  inks  and  typo- 
graphic inks  as  broad  classes  will  be  comprised  the 
various  inks  suitable  for  the  different  modifications  of 
these  two  general  processes. 

1.  Plate  Printing  Inks.  —  Hand-press  inks  should 
have  a  certain  amount  of  length  to  make  them  stand  up 


MANUFACTURE  OF  PRINTING  INK  113 

and  hold  in  the  lines  when  wiped.  This  length  is  pro- 
duced by  the  use  of  strong  oil.  Too  much  length,  how- 
ever, results  in  a  stringy,  hard-wiping  ink.  This  can  be 
remedied  by  reducing  the  amount  of  strong  oil  or  in 
cases  where  reducing  the  strong  oil  will  result  in  a  soft 
ink  the  base  can  be  increased  or  a  little  aluminum  hy- 
drate added.  Aluminum  hydrate  will  also  improve  the 
polishing  of  an  ink  when  it  has  a  tendency  to  cause 
tinting. 

Where  the  ink  is  too  soft  and  has  a  tendency  to  mash 
out  of  the  lines  the  strong  oil  should  be  increased  and  the 
medium  oil  decreased. 

If  an  ink  dries  too  quickly  the  drier  is  cut  down.  In 
some  cases  the  addition  of  medium  oil,  if  this  does  not 
make  too  soft  an  ink,  will  also  help. 

Gathering  is  generally  due  to  coarse,  dry  colors  and  can 
be  corrected  by  the  use  of  finer  raw  materials  and 
thorough  mixing.  In  some  special  cases,  the  addition  of 
other  material  will  stop  gathering.  These  special  cases 
will  be  noted  under  the  head  of  the  color  when  they 
occur. 

Inks  that  do  not  fill  in  well  are  too  stiff  and  should  be 
softened  by  the  addition  of  medium  oil. 

Power-press  inks  should  be  made  as  thin  as  it  is  pos- 
sible to  make  them  without  having  them  mash  or  pull 
out  of  the  lines.  They  only  require  length  enough  to 
make  them  feed  well  on  the  roll  and  for  this  reason 
medium  and  weak  oils  are  used  instead  of  medium  and 
strong  oil,  as  is  the  case  in  hand-press  inks.  When 
power-press  ink  pulls  out  of  the  lines  when  it  is  wiped, 
it  is  generally  too  short;  a  little  strong  oil  can  be  added 
to  correct  this.  Sometimes  this  wiping  out  is  due  to 


114        CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

too  dry  an  ink  and  it  can  be  remedied  by  adding  medium 
oil.  When  an  ink  does  not  fill  into  the  plate  well  and, 
therefore,  prints  out  light,  it  can  be  made  to  fill  in  and 
print  better  by  the  addition  of  medium  or  weak  oil. 
When  an  ink  feeds  badly  or  lacks  distribution  a  little 
strong  oil  can  be  added  to  it.  If  the  ink  has  a  tendency 
to  mash  it  should  be  stiffened  by  dropping  some  of  the 
oH. 

For  all  plate  inks  the  materials  having  the  lowest  oil 
absorptions  are  the  best.  When  the  oil  absorption  of  a 
color  is  very  great  it  is  of  no  value  as  a  plate-ink  pig- 
ment. A  pigment  of  moderately  high  oil  absorption  can 
be  mixed  with  one  of  lower  oil  absorption  or  the  oil 
absorption  can  be  reduced  by  the  addition  of  more  base. 

A  certain  amount  of  base  is  necessary  in  all  plate  inks 
except  blacks,  to  give  the  ink  grain  and  body,  to  hold  it 
in  the  lines,  to  make  the  impression  sharp  and  clear,  to 
make  it  wipe  well  without  being  too  short  and  to  improve 
the  polishing.  Without  base  the  ink  would  fill  in  badly, 
pull  out  of  the  lines,  wipe  hard,  be  sticky  and  tacky, 
and  tint  the  plate,  making  it  hard  to  polish  and  impos- 
sible to  get  a  clear  impression. 

The  tinting  of  plate  inks  should  be  done  with  zinc  white 
as  white  lead  is  heavy,  has  a  tendency  to  separate  on 
standing  and  chalks  after  being  printed  out.  It  also 
works  greasy. 

In  correcting  apparent  faults  of  inks,  the  condition  of 
the  starched  cloths  should  be  carefully  examined  as  too 
soft  or  too  stiff  a  cloth  will  cause  a  great  deal  of  differ- 
ence in  the  working  of  an  ink,  particularly  on  a  power 
press.  The  paper  also  has  some  influence  on  the  behavior 
of  the  ink;  a  paper  that  is  too  wet  or  not  wet  uniformly 


MANUFACTURE  OF  PRINTING  INK  115 

causing  a  good  deal  of  trouble  due  to  the  ink  not  taking 
hold  of  the  paper  and  therefore  giving  a  light  impression. 
Where  the  water  is  on  the  paper  in  spots  or  drops  the  ink 
at  that  particular  place  does  not  print  and  the  lines  will 
be  broken;  this  is  what  is  known  as  a  waterbreak. 

A.  Black  Plate  Inks.  —  The  highest  grade  of  black 
plate  inks  are  made  from  pure,  acid  washed  bone  black, 
finely  ground,  and  brought  to  the  proper  color  by  the 
addition  of  a  high-grade  vine  black,  and  enough  prus- 
sian  blue  to  fully  develop  the  black,  but  not  enough  to 
blue  the  under  hue. 

For  hand-press  ink  these  materials  are  mixed  to  the 
proper  consistency  with  strong  and  medium  oil;  about 
six  times  as  much  medium  oil  as  strong  oil  being  used, 
and  about  two  pounds  of  borate  of  manganese  added  to 
every  100  pounds  of  oil.  In  mixing  the  black,  the  oil 
and  drier  should  be  put  into  the  mixer  first  and  the  blacks 
and  blues  added  a  little  at  a  time  until  it  is  thoroughly 
mixed.  The  mixture  should  then  be  ground  on  a  three- 
roll  mill  once  or  twice,  according  to  smoothness. 

If  the  ink  shows  a  tendency  to  wipe  hard  the  strong 
oil  should  be  reduced.  Too  much  drying  and  stiffness 
can  be  corrected  by  adding  medium  oil.  If  the  ink  is  too 
thin  and  has  a  tendency  to  mash  add  more  strong  oil. 
If  the  addition  of  medium  oil  does  not  correct  the  drying 
or  makes  the  ink  too  thin  cut  down  the  drier. 

Gathering  can  be  lessened  by  increasing  the  medium 
oil  and  having  the  materials  ground  finer.  Coarseness 
of  raw  materials  is  a  very  prolific  cause  of  gathering.  If 
these  two  remedies  fail  to  have  the  desired  effect  a  small 
amount  of  magnetic  pigment  described  under  special 
blacks  will  be  found  to  improve  this  condition. 


Il6       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Sometimes  blacks  have  a  tendency  to  puff  up  on  the 
mill  and  to  become  spongy;  this  is  due  to  occluded  air 
in  the  black  and  it  generally  takes  place  in  air-separated 
blacks.  There  is  nothing  that  can  be  done  to  remedy 
this  condition  except  to  take  care  that  the  air  is  entirely 
gotten  out  of  the  black  in  packing. 

All  the  materials  that  go  to  make  up  blacks  should  be 
low  in  oil  absorption.  The  black  pigments  used  should 
not  require  more  than  65  parts  of  medium  oil  to  100 
parts  of  color. 

In  making  black  ink  for  use  on  power  presses,  the 
strong  oil  should  be  left  out  entirely  and  its  place  taken 
by  about  half  as  much  weak  oil  as  there  is  medium  oil. 
The  borate  of  manganese  should  also  be  increased  about 
\  pound  for  every  100  pounds  of  oil.  The  above  formula 
will  give  a  very  satisfactory  black  plate  ink,  the  cost  and 
grade  depending  on  the  kind  and  value  of  the  bone  and 
vine  blacks  used. 

Plate  inks  made  from  carbon  or  lampblack  will  not 
work  satisfactorily  as  they  lack  grain  and  body  and  have 
a  very  high  oil  absorption. 

B.  Green  Plate  Inks.  —  Fine  green  plate  inks,  made 
from  chrome  green  should  be  lightened  with  chrome 
yellow  lemon.  Chrome  green  being  very  dark  in  itself,  it 
is  never  necessary  to  shade  it.  For  cheaper  work  the 
green  can  be  lightened  with  barytes  but  this  produces  a 
pale  tint  with  blue  hue  that  is  liable  to  chalk.  When 
yellow  is  used  to  lighten  green  it  gives  a  green  of  light 
top  hue  and  slightly  yellow  under  hue.  If  a  very  light 
green  tint  is  required  zinc  white  can  be  used  with  yellow 
as  a  diluting  agent.  In  order  to  make  a  green  plate  ink, 
made  with  chrome  green  and  chrome  yellow  lemon  work 


MANUFACTURE  OF  PRINTING  INK  117 

satisfactorily,  it  is  necessary  to  use  a  base;  this  should 
be  a  water-floated  barytes  with  about  10  per  cent  of 
paris  white  in  it.  A  good  chrome  green  ink  will  stand 
about  50  per  cent  of  this  base.  The  base  makes  the  ink 
wipe  and  polish  well  and  keeps  it  from  rubbing  off. 
Chrome  green  plate  inks  dry  well  naturally  and  in  most 
cases  it  is  unnecessary  to  add  drier. 

The  green  used  for  hand  presses  should  have  about 
ij  pounds  of  strong  oil  to  every  100  pounds  of  medium 
oil  to  prevent  it  from  flowing  out  on  the  stone.  While 
green  plate  inks  are  always  used  softer  than  black  inks, 
care  should  be  taken  not  to  get  the  consistency  too  thin 
as  this  will  cause  mashing.  If  the  green  wipes  badly  the 
strong  oil  should  be  decreased  or  the  base  increased  a 
little.  A  slight  increase  of  base  also  corrects  tinting,  a 
fault  inherent  in  all  greens.  When  the  green  ink  gathers 
the  medium  oil  is  increased. 

In  mixing  greens,  the  green,  yellow  and  part  of  the 
medium  oil  should  be  mixed  and  ground  first,  being  put 
through  the  mill  once.  Then  the  base,  the  strong  oil  and 
the  rest  of  the  medium  oil  is  added  to  the  mixture  and 
the  whole  mixed  thoroughly  and  reground.  For  power- 
press  inks  the  strong  oil  is  left  out  and  enough  weak 
oil  to  bring  the  ink  to  the  proper  consistency  is  used. 

Up  to  the  present  time  there  are  no  very  satisfactory 
green  lakes  on  the  market  for  use  in  plate  inks. 

Olive  green  can  be  made  by  mixing  prussian  blue  with 
the  medium  hue  of  chrome  yellow.  This  gives  a  bright 
olive;  it  can  be  shaded  with  a  little  vine  black  or  light- 
ened with  a  little  chrome  yellow  lemon.  Its  base  should 
be  barytes.  Olive  inks  should  be  ground  about  three 
times  to  prevent  the  separation  of  the  blue  on  standing. 


n8       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

C.  Yellow  Plate    Inks.  —  The    chrome    yellows    give 
very  satisfactory  working  plate  inks  but  when   a  fine 
permanent  ink  is  desired  one  of  the  permanent  yellow 
lakes  will  be  found  not  only  to  work  better  but  also  to 
be  more  permanent  and  brighter  than  the  chrome  colors. 
The  chrome  yellows  will  carry  about  50  per  cent  of  base 
while  the  yellow  lakes  will  carry  slightly  more,  being 
stronger  and  brighter.     The  question  of  price  and  the 
class  of  work  figures  largely  in  the  choice  between  the 
chrome  yellows  and  the  yellow  lakes. 

D.  Blue    Plate    Inks.  —  The    blue  mineral  pigments 
all  make  good  working  inks  of  fairly  low  oil  absorption, 
except  ultramarine  blue  which  works  up  into  a  tacky, 
hard-working  ink.     There  are,  however,  very  permanent 
blue  lakes  without  these  faults  that  will  match  ultra- 
marine blue  in  color.     There  are  a  number  of  blue  lakes 
of  all  hues  on  the  market  that  surpass  in  working  quality 
and  permanency  all  of  the  mineral  blues,  but  they  are 
quite   expensive   as    compared   with    the   mineral   blues. 
A   small   amount  of   drier   should  be  added   to   all   the 
blues. 

E.  Red  Plate  Inks.  —  Among  the  red  inks  there  are 
no  satisfactory  ones  made  from  mineral  pigments.     Ver- 
million  and  orange  mineral,  the  latter  not  being  really 
a  red  but  an  orange,  make  very  poor  working  inks.     Ver- 
million  is  a  very  heavy  pigment  and  settles  out  from  the 
ink  and  on  this  account  causes  the  ink  to  gather  a  great 
deal  and  to  fill  in  poorly,  defects  that  it  is  impossible  to 
remedy.     Where  vermillion  must  be  used  it  should  always 
be   used   with   some   similar   hued  pigment.     Vermillion 
inks  always  require  driers. 

Orange  mineral  ink  has  the  same  defects  as  the  ver- 


MANUFACTURE  OF  PRINTING  INK  119 

million  ink  with  the  added  disadvantage  that  this  pig- 
ment exerts  a  great  drying  action  on  the  oil,  causing  the 
ink  to  harden  up  rapidly.  It  also  has  a  tendency  to 
form  a  soap  with  the  oil,  which  results  in  a  livery  mass 
that  cannot  be  worked.  Of  the  two  grades  of  orange 
mineral,  French  and  German,  the  French  orange  mineral 
is  the  better. 

Since  there  are  a  number  of  absolutely  light  and  at- 
mospherically fast  aniline  lakes  of  all  hues  of  red,  from  a 
brilliant  scarlet  to  an  orange  of  red  hue,  which  possess 
perfect  working  qualities,  it  is  an  easy  matter  to  match 
the  color  of  any  red.  The  red  lakes  will  carry  a  great 
deal  of  base  when  made  into  ink.  The  most  common 
fault  of  the  red  lakes  is  shortness  and  care  should  be 
taken  to  avoid  those  colors  that  have  a  high  oil  ab- 
sorption or  show  shortness.  The  addition  of  a  little 
more  base  will  make  an  ink  of  this  character  work 
better,  if  it  is  necessary  to  use  a  pigment  that  is  short. 
All  red  lake  inks  should  be  made  up  with  a  drier. 

F.  Degraded  Colors.  —  In  making  degraded  colors 
the  pigments  to  be  mixed  must  be  selected  with  a  view 
to  avoiding  colors  that  will  act  on  each  other  chemically. 
They  should  also  be  selected  with  reference  to  their 
specific  gravity  and  oil  absorption.  Colors  that  are 
close  to  each  other  in  specific  gravity  should  always  be 
selected,  as  this  will  prevent  the  separation  of  the  two 
colors  on  standing.  When  pigments  of  widely  different 
specific  gravity  are  used,  this  separation  will  take  place 
no  matter  how  intimately  the  ink  is  mixed  or  how  often 
it  is  ground.  Two  colors  of  relatively  high  oil  absorp- 
tion should  not  be  used  together  but  an  attempt  made  to 
secure  an  average  oil  absorption  where  it  is  necessary 


120       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

to  use  a  pigment  that  takes  a  great  deal  of  oil  by  com- 
bining it  with  one  that  takes  very  little. 

In  mixing  inks  of  degraded  colors  a  set  of  stock  colors, 
consisting  of  the  different  materials  needed  in  the  mix- 
tures and  ground  in  medium  oil,  should  be  kept  on  hand 
and  the  final  adjustment  of  top  hue  and  under  hue  made 
by  adding  from  these  stock  inks.  Care  should  be  taken 
in  making  this  final  adjustment  that  the  under  hue  is 
not  changed  too  much  in  attempting  to  bring  up  the  top 
hue  and  vice  versa. 

In  plate  printing,  both  the  under  hue  and  top  hue  must 
be  taken  into  consideration  as  they  are  both  brought  out 
in  this  work  and  it  is  necessary  to  match  a  sample  in 
both  •  these  particulars.  The  fewer  pigments  used  to 
obtain  a  color  effect  the  better  the  ink  will  be  and  the 
easier  it  will  be  to  match  at  some  future  time. 

In  matching  or  comparing  samples  printed  at  two  dif- 
ferent times,  allowance  must  be  made  for  the  time  the 
original  sheet  has  been  printed,  as  ageing  and  drying  out 
will  affect  all  inks  to  some  extent,  especially  the  under 
hue.  The  condition  of  the  plate  also  has  an  effect  on 
the  color  and  work  done  when  a  plate  is  new  will  always 
look  much  brighter  and  stronger  than  that  done  on  a 
worn  one. 

2.  Typographic  Inks.  —  Typographic  inks  are  divided 
into  a  great  number  of  special  classes,  according  to  the 
effects  to  be  produced,  different  processes  for  producing 
these  effects  and  different  styles  of  presses.  Even  inks  to 
be  used  to  accomplish  the  same  general  effect  have  often 
to  be  made  slightly  different  from  each  other  on  account 
of  variations  in  the  methods  of  use  or  in  the  kind  and 
quality  of  paper  employed. 


MANUFACTURE  OF  PRINTING  INK  121 

Basicly  typographic  inks  consist  of  a  pigment  and  a 
vehicle,  all  other  ingredients  being  added  to  produce 
some  effect  or  remedy  some  defect  due  to  the  conditions 
of  the  process  to  be  employed  or  the  style  of  press;  as 
for  instance  to  increase  or  decrease  the  drying,  to  give 
a  gloss;  to  increase  or  decrease  the  body;  to  give  length 
or  shortness.  In  all  inks,  especially  typographic  inks, 
complicated  formulas  should  be  avoided  and  the  materials 
and  effects  desired  so  studied  that  a  certain  result  is 
reached  with  the  simplest  possible  mixture  of  color  and 
vehicle. 

A.  Pigments.  —  The  best  pigments  for  use  in  typo- 
graphic work  are  the  light  and  atmospherically  fast  organic 
lakes,  made  on  aluminum  hydrate  and  blanc  fixe;  and 
as  these  can  be  obtained  in  a  number  of  different  hues 
and  colors  it  is  seldom  that  two  of  them  have  to  be 
mixed  to  produce  a  certain  color.  This  is  of  great  im- 
portance, as  frequently  the  mixture  of  two  or  more  colors 
of  different  gravity,  oil  absorption  or  working  qualities 
will  result  in  a  separation  taking  place  in  the  fountain, 
which  will  cause  trouble  in  the  feeding  and  distribution 
of  the  ink.  This  is  particularly  true  of  the  mineral  pig- 
ments which  should  never  be  used  in  typographic  inks 
except  for  the  cheaper  grades.  The  mineral  colors  are  as 
a  rule  satisfactory  for  plate  printing  inks  as  there  is  not 
the  demand  in  that  sort  of  printing  for  the  working  quali- 
ties, the  very  brilliant  colors  and  the  variety  of  hues 
that  are  called  for  in  lithographic  and  typographic 
inks. 

In  typographic  printing  there  is  a  demand  for  brilliant 
colors  of  almost  every  hue,  many  of  which  must  be 
transparent  and  the  only  way  that  inks  meeting  these 


122       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

conditions  can  be  produced  is  by  the  use  of  organic  lakes, 
principally  those  made  from  aniline  dyes.  In  cases  where 
the  ink  manufacturer  makes  his  own  lake  colors,  the 
best  procedure  and  one  that  gives  the  most  brilliancy  is 
to  grind  the  lake  directly  into  varnish  as  it  comes  from 
the  filter  press  without  any  drying,  as  drying  always 
has  a  tendency  to  dull  the  color  and  in  some  cases  even 
changes  the  hue  of  the  lake.  Where  a  lake  color  is  to  be 
dried  before  use,  the  latest  factory  practice  is  vacuum 
drying  which  does  not  affect  the  color  nearly  as  much 
as  drying  by  heat  alone  and  which  does  not  require 
nearly  as  much  care  and  attention  to  produce  a  uni- 
form product.  In  grinding  moist  lakes  into  ink,  the 
lake  should  first  be  ground  in  a  small  amount  of  heavy 
varnish  until  all  the  water  has  separated  out  and  then 
ground  with  the  other  varnishes  to  the  consistency 
desired. 

For  producing  tints  in  typographic  inks,  zinc  white 
should  be  used  while  for  making  transparent  ink,  alumi- 
num hydrate  is  the  proper  material.  In  making  a  tint 
in  typographic  work  a  very  thin  ink  with  just  enough 
tack  to  make  it  take  on  the  rollers  and  distribute,  is  most 
satisfactory  and  in  many  cases  tint  inks  are  dyes  dis- 
solved in  the  vehicle. 

B.  Vehicles. — The  use  of  the  different  vehicles  is 
dependent  on  the  class  and  cost  of  the  ink  desired.  In 
general,  for  all  high-grade  inks,  linseed  oil  varnishes  of 
different  consistencies  are  used  as  the  basic  vehicle.  In 
cheaper  inks  rosin  oil  is  used,  while  in  very  common  inks 
such  as  newspaper  and  handbill  inks,  petroleum  oils  into 
which  some  paraffine  wax  has  been  ground,  are  used. 

There  are  a  number  of  grades  of  linseed  oil  varnishes 


MANUFACTURE  OF  PRINTING  INK  123 

of  different  consistencies  as  noted  in  the  preceding  chap- 
ter on  oils  and  varnishes.  These  run  in  consistency  from 
an  oil  slightly  heavier  than  raw  linseed  oil  up  to  a  stiff 
almost  glue-like  mass.  Some  of  these  varnishes  can  be 
used  alone  but  a  typographic  ink  usually  contains  a 
mixture  of  two  or  more  of  these  grades  of  linseed  oil 
varnish  and  some  other  varnish  such  as  a  gum  varnish, 
japan  drier,  asphaltum  or  some  special  product,  added  to 
give  a  property  not  possessed  by  linseed  oil  alone.  The 
simpler,  however,  this  mixture  of  varnishes  is  made  the 
better  will  be  the  resulting  ink  and  the  more  pronounced 
will  be  the  effect  desired. 

Rosin  oil  comes  in  several  different  consistencies  which 
are  used  in  the  same  way  as  linseed  oil  varnishes,  but 
for  a  different  grade  of  work.  Rosin  oil  is  also  used  to 
correct  a  fast-drying  ink  made  from  linseed  oil  varnishes. 
Rosin  oil,  even  in  the  cheaper  grades  of  ink,  is  generally 
used  with  some  linseed  oil  varnish,  as  when  used  alone 
it  does  not  dry  of  itself  except  by  absorption  into  the 
paper  and  dries  only  to  a  certain  limited  extent  when 
used  with  metallic  driers.  Thus,  when  made  without 
linseed  oil  or  a  metallic  drier  rosin-oil  inks  rub  off  some- 
what, as  the  vehicle  is  absorbed  and  the  pigment  is  left 
on  the  surface  without  much  of  a  binder.  This  is  espe- 
cially true  when  the  printing  is  done  on  an  absorbent 
paper.  The  use  of  rosin-oil  inks  without  driers  is  never- 
theless quite  common. 

Linseed  oil  varnishes  dry  partially  by  oxidation,  that 
is  besides  being  absorbed  to  a  certain  extent  by  the  paper, 
the  varnish  itself  dries  in  a  film  around  the  pigment  so 
that  it  will  not  rub  off. 

Gum  varnishes  are  used  to  give  tack,  body  and  gloss. 


124       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

They  also  tend  to  make  the  ink  stand  out  on  the  paper 
somewhat  and  when  used  with  linseed  oil  varnishes  they 
produce  an  increased  drying  effect.  The  gum  varnishes 
are  used  with  oil  varnishes  either  alone  or  in  combina- 
tion, depending  on  the  effect  to  be  produced  and  the 
pigment  used  in  the  ink.  No  general  rule  for  the  use  of 
the  different  kinds  of  gum  varnishes  can  be  laid  down  as 
the  effects  produced  by  them  vary  somewhat  with  the 
process,  paper  and  style  of  press  used.  Experience  in 
producing  certain  effects  with  certain  combinations  is 
the  best  guide  for  their  use.  In  using  gum  varnishes, 
however,  as  small  an  amount  as  possible  to  produce  the 
effect  desired  should  be  used.  Rosin  varnishes  and  rosin- 
oil  varnishes  are  used  to  give  the  same  general  effects 
as  gum  varnishes  for  cheaper  inks;  and  are  also  used 
to  correct  the  fault  of  drying  in  inks  which  must  have  a 
rather  heavy  body. 

C.  Driers.  —  Driers  are  used  when  it  is  necessary 
to  increase  the  drying  of  an  ink  without  changing  its 
consistency,  length  or  tack  and  to  make  extremely  quick 
drying  inks.  An  ink  that  dries  slowly  and  offsets  can  be 
made  to  dry  more  rapidly  by  the  addition  of  a  gum  var- 
nish and  to  dry  quickly  by  the  addition  of  a  drier.  A 
gum  varnish  exerts  only  a  moderate  drying  action  while 
a  drier  will  make  an  ink  dry  rapidly.  The  addition  of 
a  gum  varnish  is  apt  to  change  the  consistency  or  the 
properties  of  an  ink  so  that  if  a  moderate  drying  action 
is  desired  and  the  addition  of  a  gum  varnish  will  make 
the  ink  too  stiff  or  tacky  a  drier  can  be  added  and  the 
drying  regulated  either  with  rosin  varnish  or  rosin  oil. 
As  a  general  rule  the  addition  of  the  so-called  reducers 
and  specialties  should  be  avoided;  however,  the  use  of 


MANUFACTURE  OF  PRINTING  INK  125 

soap  and  petrolatum  is  of  great  assistance  in  making  inks 
soft  or  to  make  them  work  smoothly  and  cover  well  when 
made  from  an  inferior  color. 

The  class  of  varnishes  called  long  varnishes  are  used 
to  give  length  and  flowing  qualities  to  inks.  They  are 
generally  made  on  an  asphaltum  or  wood  tar  base.  There 
are  a  number  of  ingredients  that  go  into  long  varnishes 
which  are  used  in  cases  where  the  ink  demands  greater 
or  less  length,  tack  and  body.  The  demand  for  these 
properties  determines  to  a  great  extent  what  the  com- 
position of  the  varnish  will  be. 

It  must  be  remembered  in  making  all  inks  that  fre- 
quently, with  the  same  raw  materials,  a  formula  success- 
ful in  one  case  will  give  slightly  different  results  in 
another,  especially  under  different  weather  conditions. 
This  matter  of  weather  condition  is  one  that  in  the  work- 
ing of  inks  has  not  been  given  any  very  serious  considera- 
tion, but  it  is  a  thing  that  plays  a  very  important 
part  in  the  proper  manipulation  of  many  typographic 
inks. 

D.  Offset  Inks.  —  For  offset  work  the  inks  should 
be  short  and  have  fairly  little  tack;  the  best  inks  are 
rather  stiff,  that  is,  they  carry  a  great  deal  more  pigment 
in  proportion  to  the  vehicle  than  the  ordinary  typo- 
graphic ink,  and  should  be  somewhat  buttery  in  con- 
sistency although  they  should  not  be  too  greasy  as  the 
grease  tends  to  form  a  tint  on  the  plate.  They  should 
also  be  quite  slow  drying,  as  an  ink  that  dries  even  mod- 
erately fast  will  make  frequent  washing  of  the  plate 
necessary  and  every  time  it  is  washed  the  life  of  the  plate 
is  shortened.  An  ink  that  dries  fast  or  that  is  sticky 
also  piles  up  on  the  plate  and  causes  the  lines  to  spread, 


126       CHEMISTRY  AND   TECHNOLOGY  OF  PRINTING  INKS 

which  is  also  a  serious  defect.  The  ideal  ink  for  the 
offset  press  is  one  that  has  only  a  moderate  drying 
action,  that  has  only  enough  tack  in  it  to  feed  well  and 
distribute  properly,  and  has  such  a  body  that  the  greater 
part  of  the  ink  that  goes  on  the  paper  consists  of  pigment, 
having,  however,  enough  vehicle  to  hold  the  color  with- 
out rubbing.  As  the  amount  of  ink  that  goes  on  the 
plate  is  quite  small,  it  can  easily  be  seen  that  to  get  a 
properly  colored  print  a  great  deal  of  pigment  must  be 
carried  in  a  relatively  thin  layer  of  ink. 

If  the  ink  is  too  stiff  it  can  be  reduced  with  a  weak 
lithographic  varnish,  boiled  linseed  oil  without  driers  or 
with  thin  blown  oil.  Sometimes  it  is  necessary  to  use 
petrolatum  or  paraffine  oil,  but  only  small  amounts  of 
either  of  these  should  be  used  as  they  have  a  tendency 
to  spread  the  work  on  the  plate  and  to  make  the  print- 
ing strike  through.  In  cases  where  the  ink  is  too  stiff 
and  tacky,  petrolatum,  mutton  tallow  or  lanolin  can  be 
used  in  small  quantities  with  good  effect.  Ether  and 
banana  oil  are  both  recommended  to  make  the  ink  dis- 
tribute well  and  give  greater  color,  but  our  experience 
has  been  that  an  ordinarily  soft  ink  made  from  proper 
pigments,  reduced  when  necessary  with  petrolatum  or 
paraffine  oil,  will  accomplish  more  than  these  volatile 
solvents  which  for  the  most  part  are  dissipated  before 
the  ink  leaves  the  fountain  and  which  are  not  healthy 
additions  to  the  heavy  air  of  the  average  unventilated 
press  room. 

We  have  found  that  the  best  basic  vehicle  for  offset 
inks  is  linseed  oil,  thickened  to  about  the  consistency  of 
No.  i  plate  oil  by  blowing  air  through  it  at  a  tempera- 
ture of  about  100°  C. 


MANUFACTURE  OF  PRINTING  INK  127 

A  first-class  grade  of  carbon  black  should  always  be 
used  for  blacks  and  lakes  precipitated  on  very  soft- 
grained  aluminum  hydrate  should  be  used  for  colors. 
An  ink  that  separates  out  color  or  pigment  to  the  very 
slightest  extent  should  be  avoided  as  the  slightest  piling 
on  the  plate  makes  a  very  bad  looking  job.  The  lati- 
tude allowed  on  flat-bed  or  rotary  cylinder  presses  using 
electrotypes  cannot  be  allowed  in  an  ink  for  offset  work. 

For  tints  in  offset  work  and  in  fact  for  any  colored 
work  except  black,  a  base  consisting  of  equal  parts  of 
magnesium  carbonate  ground  in  a  thin  varnish  to  a  stiff 
paste  and  a  mixture  of  zinc  white  and  aluminum  hydrate 
also  ground  in  varnish  will  be  found  not  only  a  good 
reducer  but  also  to  give  the  necessary  body  and  working 
qualities  to  the  ink. 

SECTION   TWO.     DEFECTS    OF   INKS   AND 
THEIR   REMEDIES 

The  usual  difficulties  met  with  in  using  typographic 
inks  and  their  remedies  are  as  follows: 
Working  away  from  the  ink  rollers. 
Lack  of  distribution. 
Drying  on  the  rollers. 
Offsetting. 
Flooding  the  type. 
Picking  up. 
Filling  the  forms. 
Tinting  the  forms. 
Rubbing  off  after  drying. 
Graining  on  the  roller. 
Drying  too  fast. 
Not  drying  fast  enough. 


128       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

Working  away  from  the  Ink  Rollers  in  the  Fountain.  — 

Frequently  an  ink  will  work  away  from  the  feed  roller 
in  the  fountain  and  the  result  will  be  that  the  plate  or 
forms  do  not  get  the  proper  amount  of  ink  or  the  ink 
that  is  fed,  is  not  evenly  distributed  over  the  form  or 
plate  and  a  poor  print  results.  This  is  due  primarily  to 
a  short  ink  and  this  condition  may  be  caused  either  by 
the  color  mixing  short  or  the  use  of  too  great  an  amount 
of  short  varnish.  The  remedy  for  both  these  conditions 
is  to  add  a  certain  amount  of  varnish  that  has  length. 
In  cases,  however,  where  the  pigment  is  in  itself  inherently 
short  in  all  varnishes,  it  is  best  if  possible  to  use  some 
substitute  of  the  same  color  and  hue,  that  works  properly. 
Where  the  presence  of  a  varnish  contributes  to  this  short- 
ness it  is  best,  besides  adding  a  varnish  that  will  give 
length,  to  drop  as  much  as  possible  of  the  varnishes  that 
are  causing  or  contributing  to  the  shortness  of  the  ink, 
where  this  can  be  done  without  affecting  the  results 
desired  in  the  finished  work.  This  lack  of  distribution 
or  shortness  is  sometimes  developed  in  an  ink  on  stand- 
ing but  can  be  destroyed  by  restirring  the  ink.  This  is 
probably  due  to  some  tension  in  the  particles  of  pigment 
and  is  most  frequently  encountered  in  certain  grades  of 
carbon  black. 

Lack  of  Distribution.  —  It  is  sometimes  the  case  that 
an  ink  will  work  well  and  feed  from  the  fountain  nicely 
but  will  not  distribute  on  the  ink  bed  or  rollers.  Be- 
sides being  due  to  shortness  this  is  sometimes  due  to  a 
soft  ink  and  in  these  cases  the  tack  should  be  increased 
to  such  an  extent  that  the  ink  will  take  hold  of  the  rol- 
lers easily  and  spread  over  all  their  surface.  Sometimes, 
however,  this  lack  of  distribution  is  caused  by  too  rapid 


MANUFACTURE  OF  PRINTING  INK  129 

drying,  the  remedies  for  which  are  taken  up  in  the  next 
paragraph. 

Drying  on  the  Rollers.  —  Drying  on  the  rollers  is  due 
most  often  to  an  ink  that  dries  too  rapidly  but  sometimes 
this  is  caused  by  an  ink  that  is  too  tacky  and  for  this 
reason  picks  up  and  holds  particles  of  lint  or  dust,  and 
it  is  not  infrequently  caused  by  conditions  of  the  atmo- 
sphere; so  that  an  ink  that  works  perfectly  under  the 
ordinary  conditions  will  dry  rapidly  in  a  spell  of  very 
dry  weather.  It  is  best  to  decide  first  whether  the  drying 
is  the  result  of  tackiness  and  if  this  is  the  case  the  rollers 
and  the  ink  on  them  will  contain  some  fine  particles  of 
lint  and  dust  and  not  make  a  clean  dried  film  but  a 
gummy  mass,  and  the  sheets  are  apt  to  show  where  the 
paper  has  been  picked  up.  If  the  trouble  is  from  this 
source  the  remedy  lies  in  making  the  ink  softer.  If,  how- 
ever, the  drying  is  due  to  a  quick  'drying  ink,  that  is,  if 
under  any  weather  conditions  the  ink  dries  in  a  clear 
film,  the  drier  should  be  cut  down  or  if  there  is  no  drier 
in  the  ink  and  the  drying  is  due  to  the  influence  of  the 
pigment  used  a  small  amount  of  non-drying  oil  should  be 
added.  If  the  ink,  which  has  been  running  well  under 
ordinary  weather  conditions  suddenly  begins  to  dry  too 
fast  this  condition  can  be  remedied  by  adding  a  little 
non-drying  varnish  to  the  ink  in  the  fountain  to  meet 
the  change  in  the  weather;  inks  that  dry  for  this  cause 
should  always  be  doctored  in  the  fountain  as  this  con- 
dition may  change  at  any  time. 

Offsetting.  —  Offsetting  may  be  due  to  a  number  of 
things  that  must  be  taken  up  in  order.  It  may  be  that 
the  ink  is  not  getting  its  initial  set  fast  enough,  in  which 
case  the  amount  of  drier  should  be  increased.  It  may 


130       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

be  also  due  to  lack  of  absorption  of  the  paper,  which 
may  have  two  causes:  either  the  ink  may  be  too  stiff,  in 
which  case  it  should  be  made  thinner  or  it  may  be  due 
to  a  poorly  made  paper  for  which  trouble  there  is  no 
way  of  improving  the  ink.  Offsetting  is  also  caused  by 
the  printer  allowing  too  much  ink  to  go  on  the  form  and 
this  can  be  stopped  by  cutting  down  the  feed  of  the 
fountain.  A  sticky  ink  is  also  a  cause  of  offsetting  and 
this  can  be  stopped  by  adding  petrolatum  to  the  ink 
and  where  gum  varnishes  are  being  used,  by  cutting  down 
the  proportion  of  these  varnishes. 

Sometimes,  especially  in  the  case  of  high-speed  web 
presses  and  offset  presses  a  little  paraffine  or  beeswax 
will  remedy  this  defect. 

Flooding  the  Type.  —  Flooding  the  type  or  form  is 
caused  by  the  printer  opening  his  fountain  too  wide,  the 
use  of  too  thin  an  ink  or  in  the  case  of  lithographic  or 
offset  work  the  use  of  too  little  water  or  the  absence  of  an 
etching  material  in  the  water  fountain.  Where  the  work 
in  lithographic  or  offset  printing  does  not  come  out  clear, 
it  is  well  to  add  some  etching  solution  to  the  water 
fountain. 

Picking  Up.  —  Picking  up  is  caused  either  by  too  stiff 
an  ink,  too  tacky  an  ink  or  an  ink  that  dries  too  fast 
and,  therefore,  develops  tackiness  on  the  rollers,  and  also 
by  poor  paper.  When  the  ink  is  stiff  it  should  be  thinned 
by  the  use  of  a  weak  varnish;  when  it  is  too  tacky  petro- 
latum or  a  soft  varnish  should  be  added  and  if  the  ink 
dries  too  fast  the  decreasing  of  the  drier  or  the  addition 
of  a  non-drying  varnish  should  help.  Even  when  the 
defect  is  caused  by  poor  paper  the  trouble  can  be  reme- 
died to  some  extent  by  the  use  of  the  different  materials 


MANUFACTURE  OF  PRINTING  INK  131 

described  above.  Of  course  this  must  be  the  subject  of 
experiment. 

Filling  the  Forms.  —  Filling  up  of  the  forms  or  type 
may  be  due  either  to  too  rapid  drying  or  the  use  of  a 
pigment  that  does  not  distribute  well  in  the  varnish. 
This  generally  occurs  when  the  ink  is  not  ground  well 
enough  to  make  it  smooth,  when  the  pigment  itself  is 
coarse  or  when  a  pigment  of  heavy  specific  gravity  is 
used.  Filling  up  is  also  caused  by  the  accidental  admix- 
ture of  some  foreign  matter  such  as  lint  from  the  paper, 
dirt  and  dust  from  the  air  and  the  like. 

Tinting  the  Form.  —  When  an  ink  has  a  pigment  of 
high  gravity  and  a  great  deal  of  weak  varnish  in  it  or 
when  the  ink  is  too  thin  bodied,  the  varnish  will  some- 
times separate  from  the  pigment,  particularly  when  the 
rollers  become  heated  after  a  long,  continuous  run  and 
this  varnish,  faintly  colored,  will  fill  in  between  the  lines 
and  leave  a  faint  tint  on  the  paper.  To  correct  this  fault, 
which  is  most  prevalent  on  high-speed  presses,  it  is  nec- 
essary to  give  the  ink  more  body. 

Graining  out  on  the  Rollers.  —  Tinting  is  generally 
associated  either  with  the  filling  up  of  the  form  or  the 
depositing  of  the  pigment  in  a  grainy  condition  on  the 
vibrating  rollers.  This  graining  out  on  the  rollers  is 
caused  by  the  separation  of  the  pigment,  due  to  the  char- 
acter of  the  pigment  as  explained  under  "filling  the  form" 
or  to  the  same  cause  as  that  of  tinting,  namely  the  use 
of  an  excess  of  a  thin-bodied  varnish.  The  most  satis- 
factory remedy  for  all  three  of  the  above  conditions  is 
to  use  a  better  working  pigment  or  a  heavier  bodied  var- 
nish of  little  tack. 

Rubbing  Off.  —  There  are  two  varieties  of  rubbing  off, 


132       CHEMISTRY  AND  TECHNOLOGY  OF  PRINTING  INKS 

one  where  the  ink  rubs  off  wet,  and  this  can  be  remedied 
by  adding  more  drier,  and  another  where  the  ink  comes 
off  as  a  dust,  due  to  the  absorption  of  the  vehicle  into 
the  paper,  leaving  the  pigment  on  top  in  a  powdery  form. 

This  can  best  be  remedied  by  the  use  of  a  small  amount 
of  vehicle  that  dries  by  oxidation  or  the  addition  of  soap, 
or  some  other  material  that  will  tend  to  keep  the  vehicle 
from  penetrating  into  the  paper  to  such  an  extent  that  it 
leaves  the  pigment  no  binder. 

This  kind  of  rubbing  off  is  also  caused  by  the  particles 
of  coating,  sizing  or  loading  of  the  paper  flaking  off. 
Some  pigments  have  the  tendency  to  dust  inherent  in 
themselves.  In  these  cases  the  pigment  or  paper  should 
be  changed. 


INDEX 


INDEX 


Abrasive  qualities,  definition  of 9 

Acid  value,  determination  of  in  lin- 
seed oil 23 

Aluminum    hydrate,    manufacture 

of 81 

properties  of 83-84 

Amyl  acetate 101-102 

Analysis  of,  barytes 27-28 

blacks 24-25 

calcium  sulphate 30 

chromium  colors S0^1 

ferrocyanide  blues 32-33 

inks 2-4 

linseed  oil 22-26 

lithopone 28 

orange  mineral 34 

paris  white 26-27 

ultramarine  blue 33 

vermillion 31 

white  lead 29 

zinc  oxide 30 

Aniline  lakes 87 

Asphaltum 100 

Atmospheric  influences,  definition 

of 12 

Azo-colors,  insoluble 86-87 

B 

Balances 19 

Barium   carbonate,   determination 

of  in  lithopone 29 

Barium  sulphate,  determination  of 

in  lithopone 28 

Barytes,  analysis  of 28-29 

manufacture  of 79 

properties  of 83-84 


Bases,  properties  of 78, 83, 84 

Black  plate  inks 115 

Blacks 63 

analysis  of 34~35 

Blanc  fixe,  manufacture  of 82 

properties  of 83-84 

Bleeding,  definition  of 12 

in  oil,  determination  of 37 

in  printing  inks no 

in  water,  determination  of 38 

Blending  inks 105 

Blue  plate  inks 1 18 

Break  in  linseed  oil 91 

determination  of 25-26 

Bronze  blue,  manufacture  of 43 

properties  of 44~45 

Body,  definition  of n 

Body  color,  definition  of n 

Bone  black,  acid  washed 64-65 

manufacture  of 64 

properties  of 72-73 

sugar  house 64-65 

Burnt  sienna,  properties  of 62-63 

Burnt  umber,  properties  of  .  .61,  62-63 


Calcium,    gravimetric    determina- 
tion of 26 

carbonate,    determination    of 

in  paris  white 26-27 

sulphate,  analysis  of 30 

Canary  yellow 48-49 

Carbon  black 67 

manufacture  of 68 

properties  of 72~73 

Carbon  dioxide,  determination  of  in 
white  lead 29 


136 


INDEX 


Chinese  blue,  manufacture  of 42 

properties  of 44~45 

Chrome  green,  manufacture  of 53 

properties  of 54~55 

Chrome  yellow 45-46 

manufacture  of 46 

properties  of 50,  51,  52 

Chrome  yellow,  lemon  hue,  manu- 
facture of 48-49 

properties  of 50,  51,  52 

Chrome  yellow,  orange  hue,  manu- 
facture of 55-56 

properties  of 58,  59,  60 

Chrome  yellow,  red  hue,  manufac- 
ture of 56 

properties  of 58,  59,  60 

Chromium,    determination    of    in 

chrome  green 31 

determination   of   in   chrome 

yellow 30 

oxide,  properties  of 54-55 

Citrines 62 

Color  strength,  definition  of 9 

determination  of 36 


Damar  gum 99 

Defects  of,  plate  inks  and  remedies 

for 112-120 

typographic  inks  and  remedies 

for 127-132 

Degraded  colors 119 

Dilutents 74 

Driers 102-124 

Drop  black 65 

Drying,  test  of  in  linseed  oil 23-26 

Duotone  printing  inks 112 


Ether...  ..101-102 


Fastness  to  light,  definition  of 12 

method  of  testing  for 18-19 

Ferrocyanide  blues,  analysis  of. .  .32-33 


Ferrocyanide  blues,  description  of. .  .41 

Filtering  apparatus 19 

Fineness,  definition  of 9 

determination  of 37 

Fire  point,  determination  of  in  lin- 
seed oil 23 

Flash  point,  determination  of  in  lin- 
seed oil 23 

Flow,  definition  of 10 

Fluorides,  test  for  in  barytes 27 

Foots  and  turbidity,  determination 

of  in  linseed  oil 25 

Forcing  black 65 

G 

Gas  black 67 

manufacture  of 68 

properties  of 72-73 

Gathering  of  printing  inks  . . .  in,  113, 

115,  117-118 

General  classes  of  printing  inks.  ...  112 

Graining  of  printing  inks in,  131 

Greasiness  in  printing  inks.  ...  112, 125 

Green  plate  inks 116-117 

Gum  varnishes 99, 123, 124 

H 

Hanus  solution 25 

Hard  black 65 

Hue,  definition  of 7 

Hydrometers 20 


Incompatibility,  definition  of 12 

Indian  red,  manufacture  of 61 

properties  of 62-63 

Iodine  number,  determination  of  in 

linseed  oil 25 

Iron  and  aluminum,  determination 

of 27 

J 

Japan  driers 102 

K 

Kauri  gum 99 

Kerosene  oil 98 


INDEX 


137 


Laboratory  apparatus 15-22 

Lamp  black,  effect  of  in  plate  inks.  .116 

manufacture  of 69 

properties  of 72-73 

use  in  typographic  inks 70 

Lanolin 101 

Lead,   determination   of   in   chro- 
mium colors • 30 

determination    of    in    white 

lead 29 

Length,  definition  of 10 

Liebermann-Storch  test 26 

Light,  ultraviolet 18-19 

Lime,  determination  of  in  blacks 35 

determination  of  gravimetri- 

cally 26 

Linseed  oil 88 

adulteration  of 89-91 

analysis  of 22-26 

blown 90-93, 99, 126 

break  in 25,  26,  91 

constants  of 90 

treatment  of 91-92 

varnishes 98, 123 

viscosity  of 92 

Linolate  driers 102 

Lithopone,  analysis  of 28 

manufacture  of 75~76 

properties  of 77~78 

Livach's  test 23 

Livering,  definition  of 10 

Long  varnish. 100,  124 

M 

Magnesia,  determination  of 27 

as  a  base  for  printing  inks.  79,  127 

Magnetic  pigment 70 

properties  of 71-72 

— —  use  in  plate  inks 115 

Manganese,  determination  of 32 

black 70,  72-73 

Matching  hues  of  plate  inks 120 

Mills 18, 107-109 

Mineral  black 70,  72-73 


Mixed  blacks 71 

Mixers 17,  106-107 

Muffle  furnace .,..., 16 

Muller  and  slab 15 


Oil  absorption,  definition  of 10 

effect  of  in  inks 114,  116,  119 

Offset  inks 125-127 

pigments  for 127 

reducers  for 101,  126,  127 

tints  of 127 

varnish  for 99,  126,  127 

Offsetting  of  printing  inks  no,  129,  130 

Oleic  acid 101,  102 

Opacity,  definition  of n 

Orange  mineral,  analysis  of 34 

manufacture  of 57,  58 

properties  of 58-60,  118 

Organic  lakes 84 

control  of  hue  in 85,  86 

developers  and  fixatives  for ....  86 

for  typographic  inks 121, 122 

manufacture  of 84-86 

nomenclature  of 88 

properties  of 87 

test  of 35 

Oven,  constant  temperature 16 


Paper  for  printing 114,  115 

Paraffine  oil 98 

Paris  white,  analysis  of 26,  27 

manufacture  of 80 

properties  of 83,  84 

Patent  driers 103 

Petrolatum 101 

Phosphates,  determination  of  in 

blacks 34 

Pigments,  difference  between  paint 

and  ink 5,6 

for  typographic  inks.  121,  122,  127 

Plate  oils,  apparatus  for  making 95 

from  linseed  oil 93 

from  soya  bean  oil 96 


138 


INDEX 


Plate  oils,  manufacture  of  .......  93~95 

Plate   printing   inks,    defects   and 
remedies  ..................  112-120 

-  drying  of  ..........  113,  115,  119 

-  -  effect  of  cloths  on  working  of  ...  1  14 

-  filling  in  of  .........  113,  114,  118 

-  gathering  of  ____  112,  113,  115,  118 

-  manufacture  of  ..........  112-120 

-  matching  of  .................  1  20 

-  wiping  and  polishing  of  .  .  113,  114 

117 
Primrose  yellow  ...................  48 

Printing  inks  ....................  104 

-  bleeding  of  ..................  no 

-  blending  of  .................  105 

-  defects  and  remedies  for  typo- 
graphical ......................  127 

-  duotone  ....................  112 

-  essentials  for  manufacture  .  .  .  104, 


-  gathering  of  ----  111,113,115,  117, 

118 

-  general  classes  of  ............  112 

-  graining  of  ..................  1  1  1 

-  greasing  in  .............  112,  125 

-  mills  for  grinding  ........  107-109 

-  mixers  for  ..............  106-107 

-  offsetting  of  .....  ........  no,  129 

-  permanency  of  ..............  no 

-  picking  up  of  ...........  no,  130 

-  plate  printing  ...............  112 

-  polishing  of  ........  in,  113,  114 

-  power  press  .................  113 

-  rubbing  off  of  ......  112,  113,  114 

-  striking  through  of  ...........  1  10 

-  tinting  of  plates  from.  .  .  in,  113, 

"7,  131 

-  tints  of  ........  in,  114,  122,  127 

—^-wiping  of.  .in,  113,  114,  115,  117 


Red  plate  inks 118 

Reducers 101,  102 

Remedies  for  defects  in  plate  inks, 

i i 2-1 20 


Remedies  for  defects  in  typographic 

inks 127 

Resinate  driers 102 

Rosin,  determination  of  in  linseed 

oil 26 

Rosin  oil,  consistencies  of 98,  123 

manufacture  of 97 

use  in  typographic  inks .  123 

varnish 99,    124 

Rosin  varnish 100,  124 

Rubbing  off  of  inks 112, 117, 131 

Russets .  .60 


Saponification  number,  determina- 
tion of  in  linseed  oil 24 

Shade,  definition  of 7 

Shortness,  definition  of 10 

Soap 101 

Soap  driers 102 

Soda,  determination  of  in  ultrama- 
rine blue 33 

Soft  black ..67 

Softness,  definition  of 11 

Soya  bean  oil 95 

constants  of 97 

plate  oil  from 96 

sources  of 97 

Special  blacks 71 

Specific  gravity,  determination  of 

in  linseed  oil 22 

Stearine  pitch 100 

Striking  through  of  printing  inks. .  .  no 
Sulphur,  determination  of  in  ultra- 
marine blue 33 


Tack,  definition  of 1 1 

Three  color  process,  lakes  for 87 

Tint,  definition  of 7 

Tinting  of  plates  from  printing  inks 

in,  113,  117,  131 

Tints  of  printing  inks 111-114 

Top  hue,  definition  of 8 

determination  of 37 


INDEX 


139 


Transfer  inks 101 

Transparency,  definition  of 1 1 

Tungate  driers 102 

Typographic  inks,  manufacture  of, 

102-127 
Typographic  varnish.  .98-100,  122-126 

U 

Ultramarine  blue,  analysis  of 33 

manufacture  of 43 

properties  of 44, 45,  n8 

Undertone,  definition  of 8 

determination  of 37 

Unsaponifiable  matter,  determina- 
tion of  in  linseed  oil 24 


Vehicles  for  use  in  typographic  inks  .  98, 
122,  125,  126 

Venetian  red,  manufacture  of 61 

properties  of 62-63 

Vermillion,  analysis  of 31 

manufacture  of 39 

properties  of 40, 118 

Vine  black,  manufacture  of 66,  67 

properties  of 72,  73 

Viscosimeters 20,  21 


Viscosity,  determination  of  in  oil 
and  varnish 21,    22 

W 

Water,  determination  of  in  white 

lead 29 

Water  break 115 

White  lead,  analysis  of 29 

manufacture  of 76 

properties  of 77,  78 

Wiping  cloths,  effect  of  on  inks 1 14 

Wiping  of  printing  inks  . .  in,  113, 115, 

117,  118 
Wood  tar. .  . .  100 


Yellow  plate  inks 118 


Zinc  green 54 

Zinc  oxide,  determination  of  in 

lithopone 28 

Zinc  sulphide,  determination  of  in 

lithopone 28 

Zinc  white,  manufacture  of 74 

properties  of 77~78 

Zinc  yellow 54 


A  SELECTED  LIST  OF  BOOKS  ON 

CHEMISTRY      AND       CHEMICAL 
TECHNOLOGY 

Published  by 

D.    VAN    NOSTRAND    COMPANY 

25    Park    Place  New    York 


American  Institute  of  Chemical  Engineers.  Transactions. 
8vo.  cloth.  Issued  annually.  Vol.  I.,  1908,  to  Vol. 
V.,  1912,  now  ready.  each,  net,  $6.00 

Annual  Reports  on  the  Progress  of  Chemistry.  Issued 
annually  by  the  Chemical  Society.  8vo.  cloth.  Vol.  I., 
1904,  to  Vol.  X.,  1913,  now  ready.  each,  net,  $2.00 

ASCH,  W.,  and  ASCH,  D.  The  Silicates  in  Chemistry  and 
Commerce.  Including  the  exposition  of  a  hexite  and 
pentite  theory  and  of  a  stereo-chemical  theory  of  gen- 
eral application.  Translated,  with  critical  notes  and 
additions,  by  Alfred  B.  Searle.  Illus.  6^4  x  IO-  cloth. 
476  pp.  net,  $6.00 

BAILEY,  R.  0.  The  Brewer's  Analyst.  Illustrated.  8vo. 
cloth.  423  pp.  net,  $5.00 

BARKER,  A.  F.,  and  MIDGLEY,  E.  Analysis  of  Woven 
Fabrics.  85  illustrations.  5^x8^4-  cloth.  319  pp. 

net,  $3.00 

BEADLE,  C.  Chapters  on  Papermaking.  Illustrated. 
I2mo.  cloth.  5  volumes.  each,  net,  $2.00 

BEAUMONT,  R.  Color  in  Woven  Design.  A  treatise  on 
the  science  and  technology  of  textile  coloring  (woolen, 
worsted,  cotton  and  silk  materials).  New  Edition,  re- 
written and  enlarged.  39  colored  plates.  367  illustra- 
tions. 8vo.  cloth.  369  pp.  net,  $6.00 


2  D.    VAN    NOSTRAND    COMPANY'S 

BECHHOLD,  H.  Colloids  in  Biology  and  Medicine. 
Translated  by  J.  G.  Bullowa,  M.D.  In  Press. 

BEEKMAN,  J.  M.    Principles  of  Chemical  Calculations. 

In  Press. 

BENNETT,  HUGH  G.  The  Manufacture  of  Leather, 
no  illustrations.  8vo.  cloth.  438  pp.  net,  $4.50 

BERNTHSEN,  A.  A  Text-book  of  Organic  Chemistry. 
English  translation.  Edited  and  revised  by  J.  J.  Sud- 

•     borough.    Illus.     i2mo.    cloth.    690  pp.       net,  $2.50 

BERSCH,  J.  Manufacture  of  Mineral  Lake  Pigments. 
Translated  by  A.  C.  Wright.  43  ^illustrations.  8vo. 
cloth.  476  pp.  net,  $5.00 

BEVERIDGE,  JAMES.  Papermaker's  Pocketbook.  Spe- 
cially compiled  for  paper  mill  operatives,  engineers, 
chemists  and  office  officials.  Second  and  Enlarged 
Edition.  Illus.  i2mo.  cloth.  211  pp.  net,  $4.00 

BIRCHMORE,  W.  H.  The  Interpretation  of  Gas  Analyses. 
Illustrated.  I2mo.  cloth.  75  pp.  net,  $1.25 

BLASDALE,  W.  C.  Principles  of  Quantitative  Analysis. 
An  introductory  course.  70  illus.  5^x7^.  cloth. 
404  pp.  net,  $2.50 

BLtTCHER,  H.  Modern  Industrial  Chemistry.  Trans- 
lated by  J.  P.  Millington.  Illus.  8vo.  cloth.  795 
pp.  net,  $7.50 

BLYTH,  A.  W.  Foods :  Their  Composition  and  Analysis. 
A  manual  for  the  use  of  analytical  chemists,  with  an 
introductory  essay  on  the  History  of  Adulterations. 
Sixth  Edition,  thoroughly  revised,  enlarged  and  re- 
written. Illustrated.  8vo.  cloth.  634  pp.  $7.50 

Poisons :  Their  Effects  and  Detection.     A  manual  for 

the  use  of  analytical  chemists  and  experts,  with  an 
introductory  essay  on  the  Growth  of  Modern  Toxicol- 
ogy. Fourth  Edition,  revised,  enlarged  and  rewritten. 
Illustrated.  8vo.  cloth.  772  pp.  $7.50 


LIST    OF    CHEMICAL    BOOKS 


B6CKMANN,  F.  Celluloid ;  Its  Raw  Material,  Manufac- 
ture, Properties  and  Uses.  49  illustrations.  I2mo.  cloth. 
1 20  pp.  net,  $2.50 

BOOTH,  WILLIAM  H.  Water  Softening  and  Treatment. 
91  illustrations.  8vo.  cloth.  310  pp.  net,  $2.50 

BOURCART,  E.  Insecticides,  Fungicides,  and  Weed 
Killer?.  Translated  by  D.  Grant.  8vo.  cloth.  500  pp. 

net,  $4.50 

BOURRY,  EMILE.  A  Treatise  on  Ceramic  Industries. 
A  complete  manual  for  pottery,  tile,  and  brick  manu- 
facturers. A  revised  translation  from  the  French  by 
Alfred  B.  Searle.  308  illustrations.  12  mo.  cloth. 
488  pp.  net,  $5.00 

BRISLEE,  F.  J.  An  Introduction  to  the  Study  of  Fuel. 
A  text-book  for  those  entering  the  engineering,  chem- 
ical and  technical  industries.  60  ill.  8vo.  cloth.  293 
pp.  (Outlines  of  Industrial  Chemistry.)  net,  $3.00 

BRUCE,  EDWIN  M.  Detection  of  the  Common  Food 
Adulterants.  Illus.  i2mo.  cloth.  90  pp.  net,  $1.25 

BUSKETT,  E.  W.  Fire  Assaying.  A  practical  treatise  on 
the  fire  assaying  of  gold,  silver  and  lead,  including 
descriptions  of  the  appliances  used.  Illustrated.  I2mo. 
cloth.  112  pp.  net,  $1.25 

BYERS,  HORACE  G.,  and  KNIGHT,  HENRY  G.  Notes 
on  Qualitative  Analysis.  Second  Edition,  revised. 
8vo.  cloth.  192  pp.  net,  $1.50 

CAVEN,  R.  M.,  and  LANDER,  G.  D.  Systematic  Inor- 
ganic Chemistry  from  the  Standpoint  of  the  Periodic 
Law.  A  text-book  for  advanced  students.  Illustrated. 
i2mo.  cloth.  390  pp.  net,  $2.00 

CHRISTIE,  W.  W.  Boiler-waters,  Scale,  Corrosion,  Foam- 
ing. 77  illustrations.  8vo.  cloth.  242  pp.  net,  $3.00 

Water,  Its  Purification  and  Use  in  the  Industries. 

79  illus.,  3  folding  plates,  2  colored  inserts.  I2mo. 
cloth.  230  pp.  net,  $2.00 


4  D.    VAN   NOSTRAND    COMPANY'S 

CHURCH'S  Laboratory  Guide.  A  manual  of  practical 
chemistry  for  colleges  and  schools,  specially  arranged 
for  agricultural  students.  Ninth  Edition,  revised  and 
partly  rewritten  by  Edward  Kinch.  Illustrated.  8vo. 
cloth,  365  pp.  net,  $2.50 

CORNWALL,  H.  B.  Manual  of  Blow-pipe  Analysis. 
Qualitative  and  quantitative.  With  a  complete  system 
of  determinative  mineralogy.  Sixth  Edition,  revised. 
70  illustrations.  8vo.  cloth.  '  310  pp.  net,  $2.50 

CROSS,   C.   F.,   BEVAN,   E.   J.,   and   SINDALL,   R.   W. 

Wood  Pulp  and  Its  Uses.  With  the  collaboration  of 
W.  N.  Bacon.  30  illustrations.  I2mo.  cloth.  281 
pp.  (Van  Nostrand's  Westminster  Series.)  net,  $2.00 

d'ALBE,  E.  E.  F.  Contemporary  Chemistry.  A  survey 
of  the  present  state,  methods,  and  tendencies  of  chemi- 
cal science.  I2mo.  cloth.  172  pp.  net,  $1.25 

DANBY,  ARTHUR.  Natural  Rock  Asphalts  and  Bitu- 
mens. Their  Geology,  History,  Properties  and  Indus- 
trial Application.  Illustrated.  I2mo.  cloth.  254  pp. 

net,  $2.50 

DEERR,  N.  Sugar  and  the  Sugar  Cane.  280  illustra- 
tions. 6^x9^4.  cloth.  608  pp.  net,  $8.00 

DUMESNY,  P.,  and  NOYER,  J.  Wood  Products,  Dis- 
tillates and  Extracts.  Translated  by  D.  Grant.  103 
illustrations.  8vo.  cloth.  320  pp.  net,  $4.50 

DUNSTAN,  A.  E.,  and  THOLE,  F.  B.  A  Text-book  of 
Practical  Chemistry  for  Technical  Institutes.  52  illus- 
trations. i2mo.  cloth.  345  pp.  net,  $1.40 

DYSON,  S.  S.,  and  CLARKSON,  S.  S.  Chemical  Works, 
Their  Design,  Erection,  and  Equipment.  80  illustra- 
tions, 9  folding  plates.  8vo.  cloth.  220  pp.  net,  $7.50 

ELIOT,  C.  W.,  and  STORER,  F.  H.  A  Compendious  Man- 
ual of  Qualitative  Chemical  Analysis.  Revised  with 


LIST    OF    CHEMICAL   BOOKS 


the  co-operation  of  the  authors,  by  William  R. 
Nichols.  Twenty-second  Edition,  newly  revised  by 
W.  B.  Lindsay.  111.  I2mo.  cloth.  205  pp.  net,  $1.25 

ELLIS,  C.  Hydrogenation  of  Oils,  Catalysis  and  Catalyzers, 
and  the  Generation  of  Hydrogen.  145  ill.  6x9.  cloth. 
350  pp.  net,  $4.00 

ENNIS,  WILLIAM  D.  Linseed  Oil  and  Other  Seed  Oils. 
An  industrial  manual.  88  illustrations.  8vo.  cloth. 
336  pp.  net,  $4.00 

ERMEN,  W.  F.  A.  The  Materials  Used  in  Sizing.  Their 
chemical  and  physical  properties,  and  simple  methods 
for  their  technical  analysis  and  valuation.  Illustrated. 
I2mo.  cloth.  130  pp.  net,  $2.00 

FAY,  IRVING  W.  The  Chemistry  of  the  Coal-tar  Dyes. 
8vo.  cloth.  473  pp.  net,  $4.00 

FERNBACH,  R.  L.  Chemical  Aspects  of  Silk  Manu- 
facture. i2mo.  cloth.  84  pp.  net,  $1.00 

Glue  and  Gelatine.  A  practical  treatise  on  the 

methods  of  testing  and  use.  Illustrated.  8vo.  cloth. 
208  pp.  net,  $3.00 

FISCHER,  E.  Introduction  to  the  Preparation  of  Or- 
ganic Compounds.  Translated  from  the  new  (eighth) 
German  edition  by  R.  V.  Stanford.  Illustrated. 
I2mo.  cloth.  194  pp.  net,  $1.25 

FOYE,  J.  C.  Chemical  Problems.  Fourth  Edition,  revised 
and  enlarged.  i6mo.  cloth.  145  pp.  (Van  Nos- 
trand  Science  Series,  No.  69.)  $0.50 

FRANZEN,  H.  Exercises  in  Gas  Analysis.  Translated 
from  the  first  German  edition,  with  corrections  and 
additions  by  the  author,  by  Thomas  Callan.  30  dia- 
grams. 5x7*4.  cloth.  127  pp.  net,  $1.00 

FRITSCH,  J.  The  Manufacture  of  Chemical  Manures. 
Translated  from  the  French,  with  numerous  notes,  by 
Donald  Grant.  69  illus.,  108  tables.  8vo.  cloth. 
355  pp.  net,  $4.00 


6  D.   VAN  NOSTRAND  COMPANY'S 

GROSSMANN,  J.  Ammonia  and  Its  Compounds.  Illus- 
trated. I2mo.  cloth.  151  pp.  net,  $1.25 

HALE,  WILLIAM  J.  Calculations  in  General  Chemistry. 
With  definitions,  explanations  and  problems.  Second 
Edition,  revised.  i2mo.  cloth.  185  pp.  net,  $1.00 

HALL,  CLARE  H.  Chemistry  of  Paints  and  Paint  Ve- 
hicles. 8vo.  cloth.  141  pp.  net,  $2.00 

HILDITCH,  T.  P.  A  Concise  History  of  Chemistry. 
1 6  diagrams.  I2mo.  cloth.  273  pp.  net,  $1.25 

HOPKINS,  N.  M.  Experimental  Electrochemistry :  Theo- 
retically and  Practically  Treated.  132  illustrations. 
8vo.  cloth.  298  pp.  net,  $3.00 

HOTILLEVIGUE,  L.  The  Evolution  of  the  Sciences. 
8vo.  cloth.  377  pp.  net,  $2.00 

HuBNER,  JULIUS.  Bleaching  and  Dyeing  of  Vegetable 
Fibrous  Materials.  95  illus.  (many  in  two  colors). 
8vo.  cloth.  457  pp.  (Outlines  of  Industrial  Chem- 
istry.) net,  $5.00 

HUDSON,  0.  F.  Iron  and  Steel.  An  introductory  text- 
book for  engineers  and  metallurgists.  With  a  section 
on  Corrosion  by  Guy  D.  Bengough.  47  illus.  8vo. 
cloth.  184  pp.  (Outlines  of  Industrial  Chemistry.) 

net,  $2.00 

HURST,  GEO.  H.  Lubricating  Oils,  Fats  and  Greases. 
Their  origin,  preparation,  properties,  uses,  and  analy- 
sis. Third  Edition,  revised  and  enlarged,  by  Henry 
Leask.  74  illus.  8vo.  cloth.  405  p.  net,  $4.00 

HYDE,  FREDERIC  S.  Solvents,  Oils,  Gums,  Waxes  and 
Allied  Substances.  5J4x8^.  cloth.  182  pp. 

net,  $2.00 

INGLE,  HERBERT.  Manual  of  Agricultural  Chemistry. 
Illustrated.  8vo.  cloth,  388  pp.  net,  $3.00 


LIST    OF    CHEMICAL    BOOKS 


JOHNSTON,  J.  F.  W.  Elements  of  Agricultural  Chem- 
istry. Revised  and  lewritten  by  Charles  A.  Cameron 
and  C.  M.  Aikman.  Nineteenth  Edition.  Illustrated. 
I2mo.  cloth.  502  pp.  $2.60 

JONES,  HARRY  C.  A  New  Era  in  Chemistry.  Some  of 
the  more  important  developments  in  general  chemis- 
try during  the  last  quarter  of  a  century.  Illustrated. 
I2mo.  cloth.  336  pp.  net,  $2.00 

XEMBLE,  W.  F.,  and  UNDERBILL,  C.  R.  The  Periodic 
Law  and  the  Hydrogen  Spectrum.  Illustrated.  8vo. 
paper.  16  pp.  net,  $0.50 

KERSHAW,  J.  B.  C.  Fuel,  Water,  and  Gas  Analysis,  for 
Steam  Users.  50  ill.  8vo.  cloth.  178  pp.  net,  $2.50 

-  Electro-Thermal  Methods  of  Iron  and  Steel  Produc- 
tion.    With  an   introduction  by   Dr.   J.   A.   Fleming, 
F.R.S.     50  tables,  92  illustrations.     5/^x8^4-     cloth. 
262  pp.  net,  $3.00 

KNOX,  JOSEPH.  Physico-chemical  Calculations.  i2mo. 
cloth.  196  pp.  net,  $1.00 

KOLLER,  T.  Cosmetics.  A  handbook  of  the  manufac- 
ture, employment  and  testing  of  all  cosmetic  materials 
and  cosmetic  specialties.  Translated  from  the  German 
by  Charles  Salter.  8vo.  cloth.  262  pp.  net,  $2.50 

KREMANN,  R.  The  Application  of  Physico-chemical 
Theory  to  Technical  Processes  and  Manufacturing 
Methods.  Authorized  translation  by  Harold  E.  Potts, 
M.Sc.  35  diagrams.  8vo.  cloth.  215  pp.  net,  $2.50 

KRETSCHMAR,  KARL.  Yarn  and  Warp  Sizing  in  All 
Its  Branches.  Translated  from  the  German  by  C. 
Salter.  122  illus.  8vo.  cloth.  192  pp.  net,  $4.00 

LAMBORN,  L.  L.  Modern  Soaps,  Candles  and  Glycerin. 
224  illustrations.  8vo.  cloth.  700  pp.  net,  $7.50 

-  Cotton  Seed  Products.    79  illus.  8vo.  cloth.  253  pp. 

net,  $3.00 


8  D.    VAN   MOST  RAND    COMPANY'S 

LASSAR-COHN.  Introduction  to  Modern  Scientific 
Chemistry.  In  the  form  of  popular  lectures  suited  for 
University  Extension  students  and  general  readers. 
Translated  from  the  Second  German  Edition  by  M.  M. 
Pattison  Muir.  Illus.  I2mo.  cloth.  356  pp.  $2.00 

LETTS,  E.  A.  Some  Fundamental  Problems  in  Chemis- 
try :  Old  and  New.  44  illustrations.  Svo.  cloth.  236 
pp.  net,  $2.00 

LUNGE,  GEORGE.  Technical  Methods  of  Chemical 
Analysis.  Translated  from  the  Second  German  Edition 
by  Charles  A.  Keane,  with  the  collaboration  of  eminent 
experts.  To  be  complete  in  three  volumes. 
Vol.  I.  (in  two  parts).  201  illustrations.  Svo.  cloth. 
1024  pp.  net,  $15.00 

Vol.  II.   (in  two  parts).     Illus.     6^x9.     1294 pp. 

net,  $18.00 
Vol.  III.  in  active  preparation. 

Technical  Chemists'  Handbook.  Tables  and  meth- 
ods of  analysis  for  manufacturers  of  inorganic  chemi- 
cal products.  Illus.  i2mo.  leather.  276  pp.  net,  $3.50 

Coal,  Tar  and  Ammonia.  Fourth  and  Enlarged  Edi- 
tion, In  two  volumes,  not  sold  separately.  305  illus- 
trations. Svo.  cloth.  1210  pp.  net,  $15.00 

The   Manufacture   of   Sulphuric   Acid   and   Alkali. 

A  theoretical  and  practical  treatise. 
Vol.   I.      Sulphuric  Acid.     Fourth  Edition,  enlarged. 
In  three  parts,  not  sold  separately.     543  illustrations. 
Svo.     cloth.     1665  pp.  net,  $18.00 

Vol.  II.  Sulphate  of  Soda,  Hydrochloric  Acid,  Leblanc 
Soda.  Third  Edition,  much  enlarged.  In  two  parts, 
not  sold  separately.  335  illustrations.  Svo.  cloth. 
1044  pp.  net,  $15.00 

Vol.  III.    Ammonia  Soda.    Various  Processes  cf  A1- 


LIST    OF    CHEMICAL   BOOKS 


kali-making,  and  the  Chlorine  Industry.  181  illus- 
trations. 8vo.  cloth.  784  pp.  net,  $10.00 
Vol.  IV.  Electrolytical  Methods.  In  Press. 

McINTOSH,  JOHN  G.  The  Manufacture  of  Varnish  and 
Kindred  Industries.  Illus.  8vo.  cloth.  In  3  volumes. 
Vol.  I.  Oil  Crushing,  Refining  and  Boiling;  Manu- 
facture of  Linoleum ;  Printing  and  Lithographic  Inks ; 
India  Rubber  Substitutes.  29  illus.  160  pp.  net,  $3.50 
Vol.  II.  Varnish  Materials  and  Oil  Varnish  Making. 
66  illus.  216  pp.  net,  $4.00 

Vol.  III.  Spirit  Varnishes  and  Varnish  Materials. 
64  illus.  492  pp.  net,  $4.50 

MARTIN,  G.  Triumphs  and  Wonders  of  Modern  Chem- 
istry. A  popular  treatise  on  modern  chemistry  and 
its  marvels  written  in  non-technical  language.  76  il- 
lustrations. i2mo.  cloth.  358  pp.  net,  $2.00 

MELICK,  CHARLES  W.  Dairy  Laboratory  Guide.  52 
illustrations.  I2mo.  cloth.  135  pp.  net,  $1.2? 

MERCK,  E.  Chemical  Reagents :  Their  Purity  and  Tests. 
Second  Edition,  revised.  6x9.  cloth.  210  pp.  $1.00 

MIERZINSKI,  S.  The  Waterproofing  of  Fabrics.  Trans- 
lated from  the  German  by  A.  Morris  and  H.  Robson. 
Second  Edition,  revised  and  enlarged.  29  illustrations. 
5x7^.  140  pp.  net,  $2.50 

MITCHELL,  C.  A.  Mineral  and  Aerated  Waters,  in 
illustrations.  8vo.  cloth.  244  pp.  net,  $3.00 

MITCHELL,  C.  A.,  and  PRIDEAUX,  R.  M.  Fibres  Used 
in  Textile  and  Allied  Industries.  66  illustrations. 
8vo.  cloth.  208  pp.  net,  $3.00 

MTJNBY,  A.  E.  Introduction  to  the  Chemistry  and 
Physics  of  Building  Materials.  Illus.  8vo.  cloth.  365 
pp.  (Van  Nbstrand's  Westminster  Series.)  net,  $2.00 

MURRAY,  J.  A.  Soils  and  Manures.  33  illustrations. 
8vo.  cloth.  367  pp.  (Van  Nostrand's  Westminster 
Series.)  net,  $2.00 


io  D.  VAN  NO  STRAND  COMPANY'S 

NAQUET,  A.  Legal  Chemistry.  A  guide  to  the  detec- 
tion of  poisons  as  applied  to  chemical  jurisprudence. 
Translated,  with  additions,  from  the  French,  by  J.  P. 
Battershall.  Second  Edition,  revised  with  additions. 
I2mo.  cloth.  190  pp.  $2.00 

NEAVE,  G.  B,  and  HEILBRON,  I.  M.  The  Identifica- 
tion of  Organic  Compounds.  i2mo.  ,  cloth,  in  pp. 

net,  $1.25 

NORTH,  H.  B.  Laboratory  Experiments  in  General 
Chemistry.  Second  Edition,  revised.  36  illustrations. 
5)4x724.  cloth.  212  pp.  net,  $1,00 

OLSEN,  J.  C.  A  Textbook  of  Quantitative  Chemical 
Analysis  by  Gravimetric  and  Gasornetric  Methods, 
Including  74  laboratory  exercises  giving  the  analysis 
of  pure  salts,  alloys,  minerals  and  technical  products. 
Fourth  Edition,  revised  and  enlarged.  74  illustrations. 
8vo.  cloth.,  576  pp.  net,  $4.00 

PAKES,  W.  C.  G.,  and  NANKIVELL,  A.  T.  The  Science 
of  Hygiene.  A  text-book  of  laboratory  practice.  80 
illustrations.  I2mo.  cloth.  175  pp.  net,  $1.75 

PARRY,  ERNEST  J.  The  Chemistry  of  Essential  Oils 
and  Artificial  Perfumes.  Second  Edition,  thoroughly 
revised  ond  greatly  enlarged.  Illustrated.  Svo.  cloth. 
554  pp.  net,  $5,00 

Food  and  Drugs.    In  2  volumes.    Illus.    Svo.  cloth. 

Vol.  I.     The  Analysis  of  Food  and  Drugs  (Chemical 
and  Microscopical).    59  illus.    724  pp.  net,  $7.50 

Vol.  II.     The  Sale  of  Food  and  Drugs  Acts,  1873- 
1907.     184  pp.  net,  $3.00 

PARTINCiTON,  JAMES  R.  A  Text-book  of  Thermo- 
dynamics (with  special  reference  to  Chemistry).  91 
diagrams.  Svo.  cloth.  550  pp.  net,  $4.00 

•> Higher   Mathematics   for    Chemical    Students.      44 

diagrams.     I2mo.     cloth.     272  pp.  net,  $2.00 


LIST    OF    CHEMICAL   BOOKS  n 

PERKIN,  F.  M.  Practical  Methods  of  Inorganic  Chem- 
istry. Illustrated.  i2mo.  cloth.  152  pp.  net,  $1.00 

PHILLIPS,  J.  Engineering  Chemistry.  A  practical 
treatise.  Comprising  methods  of  analysis  and  valua- 
tion of  the  principal  materials  used  in  engineering 
works.  Third  Edition,  revised  and  enlarged.  Illus- 
trated. i2mo.  cloth.  422  pp.  net,  $4.50 

PLATTNER'S  Manual  of  Qualitative  a^d  Quantitative 
Analysis  with  the  Blowpipe.  Eighth  Edition,  revised. 
Translated  by  Henry  B.  Cornwall,  assisted  by  John 
H.  Caswell,  from  the  Sixth  German  Edition,  by  Fried- 
rich  Kolbeck.  87  ill.  8vo.  cloth.  463  pp.  net,  $4.00 

POLLEYN,  F.  Dressings  and  Finishings  for  Textile 
Fabrics  and  Their  Application.  Translated  from  the 
Third  German  Edition  by  Chas.  Salter.  60  illustra- 
tions. 8vo.  cloth.  279  pp.  net,  $3.00 

POPE,  F.  G.  Modern  Research  in  Organic  Chemistry. 
261  diagrams.  I2mo.  cloth.  336  pp.  net,  $2.25 

PORBITT,  B.  D.  The  Chemistry  of  Rubber.  5x7^. 
cloth.  100  pp.  (Van  Nostrand's  Chemical  Mono- 
graphs, No.  3.)  net,  $0.75 

POTTS,  HAROLD  E.  Chemistry  of  the  Rubber  Industry. 
8vo.  cloth.  163  pp.  (Outlines  of  Industrial  Chem- 
istry.) net,  $2.00 

PRESCOTT,  A.  B.  Organic  Analysis.  A  manual  of  the 
descriptive  and  analytical  chemistry  of  certain  carbon 
compounds  in  common  use.  Sixth  Edition.  Illus- 
trated. 8vo.  cloth.  533  pp.  $5.00 

PRESCOTT,  A.  B.,  and  JOHNSON,  0.  C.  Qualitative 
Chemical  Analysis.  Sixth  Edition,  revised  and  en- 
larged. 8vo.  cloth.  439  pp.  net,  $3.50 

PRESCOTT,  A.  B.,  and  SULLIVAN,  E  C.  First  Book  in 
Qualitative  Chemistry.  For  studies  of  water  solution 
and  mass  action.  Eleventh  Edition,  entirely  reivritten. 
i2mo.  cloth.  150  pp.  net,  $1.50 


12         D.    VAN    NOSTRAND    COMPANY'S 

PRIDEAUX,  E.  B.  R.  Problems  in  Physical  Chemistry 
with  Practical  Applications.  13  diagrams.  8vo.  cloth. 
323  pp.  net,  $2.00 

PROST,  E.  Manual  of  Chemical  Analysis.  As  applied 
to  the  assay  of  fuels,  ores,  metals,  alloys,  salts,  and 
other  mineral  products.  Translated  from  the  original 
by  J.  C.  Smith.  Illus.  Svo.  cloth.  300  pp.  net,  $4.50 

PYNCHON,  T.  R.  Introduction  to  Chemical  Physics. 
Third  Edition,  revised  and  enlarged.  269  illustrations. 
Svo.  cloth.  575  pp.  $3.00 

RICHARDS,  W.  A.,  and  NORTH,  H.  B.     A  Manual  of 
Cement  Testing.      For  the  use  of  engineers  and  chem- 
ists   in   colleges   and    in   the   field.      56    illustrations. 
I2mo.     cloth.     147  pp.  net,  $1.50 

ROGERS,  ALLEN.  A  Laboratory  Guide  of  Industrial 
Chemistry.  Illustrated.  Svo.  cloth.  170  pp.  net,  $1.50 

ROGERS,  ALLEN,  and  ATIBERT,  ALFRED  B.  (Editors.) 
Industrial  Chemistry.  A  manual  for  the  student  and 
manufacturer.  Written  by  a  staff  of  eminent  special- 
ists. 340  illus.  Svo.  cloth.  872  pp.  net,  $5.00 

ROHLAND,  PAUL.  The  Colloidal  and  Crystalloidal  State 
of  Matter.  Translated  by  W.  J.  Britland  and  H.  E. 
Potts.  I2mo.  cloth.  54  pp.  net,  $1.25 

ROTH,  W.  A.  Exercises  in  Physical  Chemistry.  Author- 
ized translation  by  A.  T.  Cameron.  49  illustrations. 
Svo.  cloth.  208  pp.  net,  $2.00 

SCHERER,  R.  Casein:  Its  Preparation  and  Technical 
Utilization.  Translated  from  the  German  by  Charles 
Salter.  Second  Edition,  revised  and  enlarged.  Il- 
lustrated. Svo.  cloth.  196  pp.  net,  $3.00 

SCHIDROWITZ,  P.  Rubber.  Its  Production  and  Indus- 
trial Uses.  Plates,  83  illus.  Svo.  .cloth.  320  pp. 

net,  $5.00 

SCHWEIZER,  V.  Distillation  of  Resins,  Resinate  I^ke-. 
and  Pigments.  Illustrated.  Svo.  cloth,  i83pp.net,  $3.50 


LIST    OF    CHEMICAL   BOOKS  13 

SCOTT,  W.  W.  Qualitative  Chemical  Analysis.  A  labo- 
ratory manual.  Second  Edition,  thoroughly  revised. 
Illus.  8vo.  cloth.  1 80  pp.  net,  $1.50 

SCUDDER,  HEYWARD.  Electrical  Conductivity  and 
lonization  Constants  of  Organic  Compounds.  6x9. 
cloth.  575  pp.  net,  $3.00 

SEARLE,  ALFRED  B.  Modern  Brickmaking.  260  illus- 
trations. 8vo.  cloth.  449  pp.  net,  $5.00 

Cement,    Concrete    and    Bricks.       113    illustrations. 

5K  x8>4.    cloth.    415  pp.  net,  $3.00 

SEIDELL,  A.  Solubilities  of  Inorganic  and  Organic  Sub- 
stances. A  handbook  of  the  most  reliable  quantitative 
solubility  determinations.  Second  Printing,  corrected. 
8vo.  cloth.  367  pp.  net,  $3.00 

SENTER,  G.  Outlines  of  Physical  Chemistry.  Second 
Edition,  revised.  Illus.  I2mo.  cloth.  401  pp.  $1.75 

A  Text-book  of  Inorganic  Chemistry.  90  illustra- 
tions. I2mo.  cloth.  595  pp.  net,  $1.75 

SEXTON,  A.  H.  Fuel  and  Refractory  Materials.  Second 
Ed. .revised.  104  illus.  i2mo.  cloth.  374  pp.  net,  $2.00 

Chemistry  of  the  Materials  of  Engineering.  Illus. 

i2mo.  cloth.  344  pp.  net,  $2.50 

SIMMONS,  W.  H.,  and  MITCHELL,  C.  A.  Edible  Fats 
and  Oils.  Their  .composition,  manufacture  and  analy- 
sis. Illustrated.  8vo.  cloth.  164  pp.  net,  $3.00 

SINDALL,  R.  W.  The  Manufacture  of  Paper.  58  illus. 
8vo.  cloth.  285  pp  .  (Van  Nostrand's  Westminster 
Series.)  net,  $2.00 

SINDALL,  R.  W.,  and  BACON,  W.  N.  The  Testing  of 
Wood  Pulp.  A  practical  handbook  for  the  pulp  and 
paper  trades.  Illus.  8vo.  cloth.  150  pp.  net,  $2.50 


14         D.    VAN   NOSTRAND    COMPANY'S 

SMITH,  W.  The  Chemistry  of  Hat  Manufacturing. 
Revised  and  edited  by  Albert  Shonk.  Illustrated. 
I2mo.  cloth.  132  pp.  net,  $3.00 

SOUTHCOMBE,  J.  E.  Chemistry  of  the  Oil  Industries. 
Illus.  8vo.  cloth.  209  pp.  (Outlines  of  Industrial 
Chemistry.)  net,  $3.00 

SPEYERS,  C.  L.  Text-hook  of  Physical  Chemistry.  20 
illustrations.  8vo.  cloth.  230  pp.  net,  $2.25 

STEVENS,  H.  P.  Paper  Mill  Chemist.  67  illustrations. 
82  tables.  i6mo.  cloth.  280  pp.  net,  $2.50 

SUDBOROUGH,  J.  J.,  and  JAMES,  J.  C.  Practical  Or- 
ganic Chemistry.  92  illustrations.  i2mo.  cloth. 
394  PP-  net,  $2.00 

TERR¥,  H.  L.  India  Rubber  and  Its  Manufacture. 
18  illustrations.  8vo.  cloth.  303  pp.  (Van  Nos- 
trand's  Westminster  Series.)  net,  $2.00 

TITHERLEY,  A.  W.  Laboratory  Course  of  Organic 
Chemistry,  Including  Qualitative  Organic  Analysis. 
Illustrated.  8vo.  cloth.  235  pp.  net,  $2.00 

TOCH,  M.  Chemistry  and  Technology  of  Mixed  Paints. 
New  Edition,  in  two  volumes.  In  Preparation. 

TOCH,  M.  Materials  for  Permanent  Painting.  A  manual 
for  manufacturers,  art  dealers,  artists,  and  collectors. 
With  full-page  plates.  Illustrated.  I2mo.  cloth. 
208  pp.  net,  $2.00 

TUCKER,  J.  H.  A  Manual  of  Sugar  Analysis.  Sixth 
Edition.  43  illustrations.  8vo.  cloth.  353  pp.  $3.50 

UNDERWOOD,  N.,  and  SULLIVAN,  T.  V.  Chemistry  and 
Technology  of  Printing  Inks.  In  Press. 

VAN  NOSTRAND'S  Chemical  Annual.  Edited  by  John 
C.  Olsen  and  Alfred  Melhado.  A  handbook  of  useful 
data  for  analytical  manufacturing  and  investigating 


LIST    OF    CHEMICAL   BOOKS  15 

chemists  and  chemical  students.   Third  Issue,  enlarged. 
5x7^.    leather.    683  pp.  net,  $2.50 

VINCENT,  C.  Ammonia  and  Its  Compounds.  Their 
manufacture  and  uses.  Translated  from  the  French 
by  M.  J.  Salter.  32  ill.  8vo.  cloth.  113  pp.  net,  $2.00 

VON  GEORGIEVICS,  G.  Chemical  Technology  of  Textile 
Fibres.  Translated  from  the  German  by  Charles 
Salter.  47  illustrations.  8vo.  cloth.  320  pp.  net,  $4.50 

Chemistry  of  Dyestuffs.  Translated  from  the  Sec- 
ond German  Edition  by  Charles  Salter.  8vo.  cloth. 
412  pp.  net,  $4.50 

WADMORE,  J.  M.  Elementary  Chemical  Theory.  Illus. 
i2mo.  cloth.  286pp.  net,  $1.50 

WALKER,  JAMES.  Organic  Chemistry  for  Students  of 
Medicine.  Illus.  6x9.  cloth.  328  pp.  net,  $2.50 

WANKLYN,  J.  A.  Milk  Analysis.  A  practical  treatise 
on  the  examination  of  milk  and  its  derivatives,  cream, 
butter  and  cheese.  Illus.  I2mo.  cloth.  73  pp.  $1.00 

Water  Analysis.  A  practical  treatise  on  the  exami- 
nation of  potable  water.  Eleventh  Edition,  revised,  by 
W.  J.  Cooper.  Illus.  I2mo.  cloth.  213  pp.  $2.00 

WARNES,  A.  R.  Coal  Tar  Distillation  and  Working  Up 
of  Tar  Products.  67  illustrations.  5^x8^.  cloth. 
197  pp.  net,  $2.50 

WILSON,  F.  J.,  and  HEILBRON,  I.  M.  Chemical  Theory 
and  Calculations.  An  elementary  text-book.  Illus.,  3 
folding  plates.  121110.  cloth.  145  pp.  net,  $1.00 

WINKLER,  C.,  and  LUNGE,  G.  Handbook  of  Technical 
Gas  Analysis.  Second  English  Edition.  Illustrated. 
8vo.  cloth.  190  pp.  $4.00 

WOOD,  J.  K.  The  Chemistry  of  Dyeing.  5x7^.  cloth. 
87  pp.  (Van  Nostrand's  Chemical  Monographs,  No. 
2.)  net,  $0.75 


16  LIST   OF   CHEMICAL  BOOKS 

WORDEN,  E.  C.  The  Nitrocellulose  Industry.  A  com- 
pendium of  the  history,  chemistry,  manufacture,  com- 
mercial application,  and  analysis  of  nitrates,  acetates, 
and  xanthates  of  cellulose  as  applied  to  the  peaceful 
arts.  With  a  chapter  on  gun  cotton,  smokeless  pow- 
der and  explosive  cellulose  nitrates.  Illustrated. 
8vo.  cloth.  Two  volumes.  1239  PP-  ne*>  $10.00 

Cellulose  Acetate.  A  monograph  of  the  history, 

chemistry,  manufacture,  technical  applications  and 
analysis  of  the  non-explosive  esters  of  cellulose  and 
starch.  Illus.  I2mo.  cloth.  In  Press. 

WREN,  HENRY.  Organometallic  Compounds  of  Zinc  and 
Magnesium.  5x7^.  cloth.  108  pp.  (Van  Nos- 
trand's  Chemical  Monographs,  No.  i.)  net,  $0,75 


Any  book  in  this  list  sent  postpaid  anywhere  in  the 
world  on  receipt  of  price. 

D.    VAN    NOSTRAND    COMPANY 

Publishers  and  Booksellers 
25    PARK    PLACE  NEW    YORK 


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